UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE

SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant  ☒                                     Filed by a Party other than the Registrant  ☐

Check the appropriate box:

ASPEN INSURANCE HOLDINGS LIMITED

(Name of Registrant as Specified In Its Charter)

(Name of person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

November 6, 2018

Dear Aspen Insurance Holdings Limited Shareholder:

You are cordially invited to attend a special general meeting of the shareholders of Aspen Insurance Holdings Limited (“Aspen,” the “Company,” “our,” “us,” or “we”), which will be held at Aspen’s office located at 141 Front Street, Hamilton HM19, Bermuda, on December 10, 2018, commencing at 9:00 a.m., local time, or any adjournment thereof.

At the special general meeting, you will be asked to consider and vote on a proposal to approve the Agreement and Plan of Merger, dated as of August 27, 2018 (as it may be amended from time to time, the “merger agreement”), by and among Highlands Holdings, Ltd., a Bermuda exempted company (“Parent”), Highlands Merger Sub, Ltd., a Bermuda exempted company and wholly owned subsidiary of Parent (“Merger Sub”), and the Company. Parent is a Bermuda exempted company and an affiliate of the Apollo Funds (as defined in the accompanying proxy statement). Pursuant to the merger agreement, (i) Merger Sub will be merged with and into the Company (the “merger”), (ii) the separate corporate existence of Merger Sub will cease and (iii) the Company will continue its corporate existence under Bermuda law as the surviving company in the merger. Parent will own 100% of the ordinary shares of the Company immediately following the merger.

Pursuant to the terms and subject to the conditions set forth in the merger agreement, at the effective time of the merger (the “effective time”), each ordinary share of Aspen, $0.015144558 par value per ordinary share (each an “ordinary share” and collectively, the “ordinary shares”), issued and outstanding immediately prior to such time

(other than ordinary shares owned by Aspen as treasury shares, owned by any subsidiary of Aspen or owned by Parent, Merger Sub or any subsidiary of Parent, which will be canceled as set forth in the merger agreement) will be converted into the right to receive $42.75 in cash, without interest and less any required withholding taxes (the “merger consideration”). Our issued and outstanding 5.95% fixed-to-floating rate perpetual non-cumulative preference shares (the “5.95% preference shares”) and 5.625% perpetual non-cumulative preference shares (the “5.625% preference shares” and, together with the 5.95% preference shares, the “preference shares”) will each remain issued and outstanding as preference shares of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged.

We are soliciting proxies for use at the special general meeting or any adjournment thereof to consider and vote upon proposals to approve: (1) an amendment to the Aspen bye-laws to reduce the shareholder vote required to approve a merger with any third party from the affirmative vote of at least 66% of the voting power of the shares entitled to vote at a meeting of the shareholders to a simple majority of the votes cast at a meeting of the shareholders (the “bye-law amendment proposal”), (2) the merger agreement, the statutory merger agreement required in accordance with Section 105 of the Bermuda Companies Act 1981, as amended (the “Companies Act”), and the merger (the “merger proposal”), (3) on an advisory (non-binding) basis, the compensation that may be paid or become payable to Aspen’s named executive officers in connection with the merger, as described in the accompanying proxy statement (the “compensation advisory proposal”); and (4) an adjournment of the special general meeting, if necessary or appropriate, to solicit additional proxies, in the event that there are insufficient votes to approve the bye-law amendment proposal or the merger proposal at the special general meeting (the “adjournment proposal”). Holders of ordinary shares will be entitled to vote on all four proposals described above, whereas holders of preference shares will be entitled to vote only on the merger proposal and the adjournment proposal. We urge all shareholders to read the accompanying proxy statement and the documents included with the accompanying proxy statement carefully and in their entirety.

Aspen’s board of directors (the “Board”) has unanimously, by all directors present at a duly called meeting, adopted resolutions whereby it has (1) determined that the bye-law amendment is advisable and in the best interests of Aspen, and authorized and approved the bye-law amendment, (2) determined that the merger consideration constitutes no less than fair value for each ordinary share in accordance with the Companies Act, that the preference shares of the surviving company constitutes fair value for each of the preference shares of Aspen in accordance with the Companies Act and that the merger, on the terms and subject to the conditions set forth in the merger agreement and the statutory merger agreement, is fair to and in the best interests of, Aspen and its shareholders, (3) approved the merger, the merger agreement and the statutory merger agreement, and (4) resolved to recommend approval of the bye-law amendment, the merger, the merger agreement, and the statutory merger agreement to Aspen’s shareholders for their consideration at the special general meeting. Accordingly, the Board recommends that Aspen’s shareholders vote “FOR” the bye-law amendment proposal, “FOR” the merger proposal, “FOR” the compensation advisory proposal and “FOR” the other proposals described in the accompanying proxy statement in respect of which they are entitled to vote.

If the bye-law amendment proposal is approved, the bye-law amendment will be effective immediately and prior to the vote on the merger proposal, so that the affirmative vote of a majority of the votes cast at the special general meeting or any adjournment thereof at which a quorum under Aspen’s bye-laws is present will be required to approve the merger proposal. If the bye-law amendment proposal is not approved, the affirmative vote of at least 66% of the voting power of shares entitled to vote at the special general meeting or any adjournment thereof at which a quorum under Aspen’s bye-laws is present will be required to approve the merger proposal. Approval of the merger proposal by holders of Aspen’s ordinary shares and preference shares, voting as one class, is necessary to complete the merger.

Your vote is very important. Whether or not you plan to attend the special general meeting, please take the time to complete, date, sign and return the enclosed proxy card in the accompanying prepaid reply envelope, or submit your proxy by telephone or through the Internet. We ask that you do so as promptly as possible to ensure that your shares may be represented and voted at the special general meeting or any adjournment thereof. You may revoke a submitted proxy prior to its exercise by either giving notice of such revocation to the General Counsel

of Aspen in writing at Aspen Insurance Holdings Limited, 141 Front Street, Hamilton HM19, Bermuda, or attending and voting in person at the special general meeting or by executing a subsequent proxy, provided that such action is taken in sufficient time to permit the necessary examination and tabulation of the subsequent proxy or revocation before the votes are taken.

If your ordinary shares or preference shares are held in street name by your bank, brokerage firm or other nominee, your bank, brokerage firm or other nominee, as applicable, will not be permitted to vote your shares without instructions from you. You should instruct your bank, brokerage firm or other nominee as to how to vote your shares by following the procedures provided by your bank, brokerage firm or other nominee. You also will not be able to vote your shares in person at the special general meeting or any adjournment thereof unless you obtain a legal proxy form from your broker, bank or other nominee.

The accompanying proxy statement provides you with detailed information about the special general meeting, the bye-law amendment, the merger agreement, the merger and the compensation that may be paid or become payable to Aspen’s named executive officers in connection with the merger. A copy of the merger agreement is attached as Annex A-1 to the accompanying proxy statement. A copy of the statutory merger agreement is attached as Annex A-2 to the accompanying proxy statement. A copy of the bye-law amendment is attached as Annex A-3 to the accompanying proxy statement. We encourage you to read the entire proxy statement and its annexes, including the merger agreement, carefully.

If you have any questions or need assistance voting your shares, please call Innisfree M&A Incorporated, Aspen’s proxy solicitor, toll-free at (888) 750-5834 from the United States and Canada or (412) 232-3651 from other locations.

Thank you in advance for your cooperation and continued support.

Sincerely,

Michael Cain

Group General Counsel and Company Secretary

Hamilton, Bermuda

November 6, 2018

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE MERGER AGREEMENT OR THE TRANSACTIONS CONTEMPLATED THEREBY, INCLUDING THE MERGER, PASSED UPON THE MERITS OR FAIRNESS OF THE MERGER OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THIS DOCUMENT. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The accompanying proxy statement is dated as of November 6, 2018 and is first being mailed to shareholders on or about November 7, 2018.

ASPEN INSURANCE HOLDINGS LIMITED

NOTICE OF SPECIAL GENERAL MEETING OF SHAREHOLDERS

November 6, 2018

Dear shareholders:

On August 27, 2018, Aspen Insurance Holdings Limited (“Aspen”) entered into an Agreement and Plan of Merger (as it may be amended from time to time, the “merger agreement”) with Highlands Holdings, Ltd. (“Parent”) and Highlands Merger Sub, Ltd., a wholly-owned subsidiary of Parent (“Merger Sub”). Parent is a Bermuda exempted company and an affiliate of the Apollo Funds (as defined in the accompanying proxy statement). Pursuant to the merger agreement and a statutory merger agreement that is an exhibit to the merger agreement, Merger Sub will be merged with and into Aspen, with Aspen surviving the merger as a wholly-owned subsidiary of Parent (the “merger”).

Notice is hereby given that a special general meeting of shareholders (the “special general meeting”) of Aspen will be held at Aspen’s office located at 141 Front Street, Hamilton HM19, Bermuda, on December 10, 2018 at 9:00 a.m., local time, for the following proposals:

Consummation of the merger is conditioned on, among other things, the approval of the merger proposal, but is not conditioned on the approval of the bye-law amendment proposal, the compensation advisory proposal or the adjournment proposal.

Your vote is very important. Whether or not you plan to attend the special general meeting, please take the time to complete, date, sign and return the enclosed proxy card in the accompanying prepaid reply envelope, or submit your proxy by telephone or through the Internet. We ask that you do so as promptly as possible to ensure that your shares may be represented and voted at the special general meeting.

You may revoke a submitted proxy prior to its exercise by either giving notice of such revocation to the General Counsel of Aspen in writing at Aspen Insurance Holdings Limited, 141 Front Street, Hamilton HM19, Bermuda, or attending and voting in person at the special general meeting or by executing a subsequent proxy, provided that such action is taken in sufficient time to permit the necessary examination and tabulation of the subsequent proxy or revocation before the votes are taken.

Aspen’s board of directors (the “Board”) has unanimously, by all directors present at a duly called meeting, adopted resolutions whereby it has (1) determined that the bye-law amendment is advisable and in the best interests of Aspen, and authorized and approved the bye-law amendment, (2) determined that the merger consideration constitutes no less than fair value for each ordinary share in accordance with the Companies Act, that the preference shares of the surviving company constitutes fair value for each of the preference shares of Aspen in accordance with the Companies Act and that the merger, on the terms and subject to the conditions set forth in the merger agreement and the statutory merger agreement, is fair to, and in the best interests of, Aspen and its shareholders, (3) approved the merger, the merger agreement and the statutory merger agreement, and (4) resolved to recommend approval of the bye-law amendment, the merger, the merger agreement, and the statutory merger agreement to Aspen’s shareholders for their consideration at the special general meeting. Accordingly, the Board recommends that Aspen shareholders vote “FOR” the bye-law amendment proposal, “FOR” the merger proposal, “FOR” the compensation advisory proposal and “FOR” the other proposals described in the accompanying proxy statement in respect of which they are entitled to vote.

For purposes of Section 106(2)(b)(i) of the Companies Act, the Board has unanimously, by all directors present at a duly called meeting, determined that the fair value for (i) each ordinary share to be no greater than $42.75, without interest and less any applicable withholding taxes, (ii) each 5.95% preference share to be the continuation of each such preference share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged and (iii) each 5.625% preference share to be the continuation of each such preference share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged. Aspen’s shareholders who are not satisfied that they have been offered fair value for their shares and whose shares are not voted in favor of the merger proposal may exercise their appraisal rights under the Companies Act to have the fair value of their shares appraised by the Supreme Court of Bermuda (the “Bermuda Court”). Aspen’s shareholders intending to exercise appraisal rights MUST file their application for appraisal of the fair value of their shares with the Bermuda Court within ONE MONTH of the giving of the notice convening the special general meeting and otherwise fully comply with the requirements for seeking appraisal under the Companies Act.

By order of the Board of Directors,

Michael Cain

Group General Counsel and Company Secretary

Hamilton, Bermuda

November 6, 2018

TABLE OF CONTENTS

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ASPEN INSURANCE HOLDINGS LIMITED

SPECIAL GENERAL MEETING OF SHAREHOLDERS

TO BE HELD ON DECEMBER 10, 2018

PROXY STATEMENT

This proxy statement contains information related to a special general meeting of shareholders of Aspen Insurance Holdings Limited (“Aspen,” the “Company,” “we,” “us” or “our”), which will be held at Aspen’s office located at 141 Front Street, Hamilton HM19, Bermuda, on December 10, 2018, at 9:00 a.m., local time, and any adjournments or postponements thereof. We are furnishing this proxy statement to shareholders of Aspen as part of the solicitation of proxies by the board of directors of Aspen (the “Board of Directors” or the “Board”) for use at the special general meeting. This proxy statement is dated as of November 6, 2018 and is first being mailed to shareholders of Aspen on or about November 7, 2018.

SUMMARY

This summary highlights the material information in this proxy statement. To fully understand Aspen’s proposals and for a more complete description of the legal terms of the merger and the bye-law amendment, you should carefully read this entire proxy statement, including the annexes and documents incorporated by reference herein, and the other documents to which Aspen has referred you. For information on how to obtain the documents that are on file with the United States Securities and Exchange Commission (the “SEC”), please see the section of this proxy statement titled “Where You Can Find Additional Information.”

Parties to the Merger (Page 23)

Aspen Insurance Holdings Limited

Aspen Insurance Limited

141 Front Street

Hamilton, Bermuda HM19

Telephone: (441) 295-8201

Aspen, a Bermuda exempted company, provides reinsurance and insurance coverage to clients in various domestic and global markets through wholly-owned subsidiaries and offices in Australia, Bermuda, Canada, Ireland, Singapore, Switzerland, the United Arab Emirates, the United Kingdom and the United States. For the year ended December 31, 2017, Aspen reported $12.9 billion in total assets, $6.7 billion in gross reserves, $2.9 billion in total shareholders’ equity and $3.4 billion in gross written premiums. Its operating subsidiaries have been assigned a rating of “A” by Standard & Poor’s Financial Services LLC, an “A” (“Excellent”) by A.M. Best Company Inc. and an “A2” by Moody’s Investors Service, Inc.

For additional information on Aspen and its business, including how to obtain the documents that Aspen has filed with the SEC, please see the section of this proxy statement titled “ Where You Can Find Additional Information.”

Highlands Holdings, Ltd.

Highlands Holdings, Ltd.

c/o Apollo Management IX, L.P.

9 West 57th Street, 43rd Floor

New York, NY 10019

Telephone: (212) 515-3200

Parent is a Bermuda exempted company and an affiliate of the Apollo Funds (as defined in the section entitled “Summary-Financing” beginning on page 6), which are managed by Apollo Management IX, L.P.

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(“Apollo Management”). We refer to Apollo Management, acting on behalf of the Apollo Funds, as “Apollo.” Parent, Apollo Management and the Apollo Funds are affiliates of Apollo Global Management, LLC, which we refer to as “AGM.” AGM is a leading global alternative investment manager with offices in New York, Los Angeles, Houston, Bethesda, London, Frankfurt, Madrid, Luxembourg, Mumbai, Delhi, Singapore, Hong Kong and Shanghai. AGM had assets under management of approximately $270 billion as of June 30, 2018 in private equity, credit and real estate funds invested across a core group of nine industries where AGM has considerable knowledge and resources. Parent was formed solely for the purpose of engaging in the merger and other related transactions and to serve as the holding company of Merger Sub. Parent has not engaged in any business other than in connection with the merger and other related transactions.

Highlands Merger Sub, Ltd.

Highlands Merger Sub, Ltd.

c/o Apollo Management IX, L.P.

9 West 57th Street, 43rd Floor

New York, NY 10019

Telephone: (212) 515-3200

Highlands Merger Sub, Ltd., a Bermuda exempted company (“Merger Sub”), is a wholly-owned subsidiary of Parent that was formed by Parent solely for purposes of entering into the merger agreement and the statutory merger agreement and completing the transactions contemplated thereby. Merger Sub has not engaged in any business other than in connection with the merger and other related transactions. Upon completion of the merger, Merger Sub will be merged with and into Aspen and Merger Sub will cease to exist.

The Merger (Page 24)

Pursuant to the merger agreement and the statutory merger agreement required in accordance with Section 105 of the Companies Act (the “statutory merger agreement”), Merger Sub will merge with and into Aspen, with Aspen continuing as the surviving company. Aspen, as the surviving company, will continue in existence as a Bermuda exempted company and as a wholly-owned subsidiary of Parent. As a result of the merger, under Bermuda law, Aspen’s and Merger Sub’s respective undertakings, property and liabilities will become vested in Aspen as the surviving company in the merger. Subject to Parent’s ability to delay closing in certain circumstances to determine the amount, if any, of net CAT losses, the closing of the merger (the “closing”) will occur on the third business day following the satisfaction or waiver of all closing conditions set forth in the merger agreement (other than those conditions that by their nature are to be satisfied at the closing, but subject to the satisfaction or waiver of those conditions) or such other date and time as Aspen and Parent may agree in writing. The merger will be effective upon the issuance of a certificate of merger by the Bermuda Registrar of Companies and at the time and date shown on such certificate of merger (the “effective time”).

Merger Consideration (Page 24)

At the effective time, each ordinary share of Aspen issued and outstanding immediately prior to the effective time (other than ordinary shares owned by Aspen as treasury shares, owned by any subsidiary of Aspen or owned by Parent or Merger Sub or any subsidiary thereof, which will be canceled as set forth in the merger agreement) will be canceled and converted into the right to receive $42.75 in cash, without interest and less any required withholding taxes (the “merger consideration”).

Preference Shares (Page 24)

At the effective time, each 5.95% preference share and each 5.625% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged. Following the merger, Parent may cause the surviving company to exercise any of its rights with respect to each 5.95% preference share and each 5.625% preference share issued and outstanding.

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The Statutory Merger Agreement (Page A-2-1)

The statutory merger agreement, together with the merger agreement, governs the legal effects of the merger under Bermuda law. A copy of the statutory merger agreement is attached as Annex A-2 to this proxy statement.

Time, Place and Purpose of the Special General Meeting (Page 103)

The special general meeting will be held on December 10, 2018, starting at 9:00 a.m., local time, at Aspen’s office located at 141 Front Street, Hamilton HM19, Bermuda. At the special general meeting, Aspen’s shareholders will be asked to consider and vote on each of the following proposals:

Ordinary shares issued and outstanding as of the record date will be entitled to vote on each of the above proposals. Preference shares outstanding as of the record date will have the right to vote only on Proposal 2 and Proposal 4.

Consummation of the merger is conditioned on, among other things, the approval of Proposal 2 above, but is not conditioned on the approval of Proposals 1, 3 or 4.

Record Date (Page 104)

Only shareholders of record, as shown on Aspen’s registers of members, at the close of business on November 2, 2018, the record date for the special general meeting, will be entitled to notice of, and to vote at, the special general meeting or any adjournment or postponement thereof. As of November 2, 2018, the record date for the special general meeting, there were 59,698,802 ordinary shares, par value $0.015144558 per ordinary share, 11,000,000 5.95% preference shares and 10,000,000 5.625% preference shares issued and outstanding.

Quorum (Page 104)

Each ordinary share and preference share carries the right to vote on the merger proposal and the adjournment proposal. Accordingly, the quorum required at the special general meeting to consider the merger proposal and the adjournment proposal is the presence in person or by proxy of at least one shareholder representing in excess of 50% of the combined total voting power of all ordinary and preference shares as of the record date. Only the ordinary shares carry the right to vote on the bye-law amendment proposal and the compensation advisory proposal. Accordingly, the quorum required at the special general meeting to consider the bye-law amendment proposal and the compensation advisory proposal is the presence in person or by proxy of at least one shareholder representing in excess of 50% of the total voting power of all ordinary shares as of the record date.

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Required Shareholder Votes (Page 104)

The approval of the bye-law amendment proposal requires the affirmative vote of at least 66% of the voting power of ordinary shares in accordance with Aspen’s bye-laws. Preference shares do not have the right to vote on the bye-law amendment proposal.

If the bye-law amendment proposal is approved, the bye-law amendment will be effective immediately and prior to the vote on the merger proposal, so that the approval of the merger proposal will require the affirmative vote of a majority of the votes cast by holders of ordinary shares and preference shares, voting as one class, at the special general meeting or any adjournment thereof in accordance with Aspen’s bye-laws. If the bye-law amendment proposal is not approved, the approval of the merger proposal will require the affirmative vote of at least 66% of the voting power of ordinary shares and preference shares entitled to vote, voting as one class, at the special general meeting or any adjournment thereof in accordance with Aspen’s bye-laws.

The approval of the compensation advisory proposal requires the affirmative vote of a majority of the votes cast by holders of ordinary shares at the special general meeting in accordance with Aspen’s bye-laws. Preference shares do not have the right to vote on the compensation advisory proposal.

The approval of the adjournment proposal requires the affirmative vote of a majority of the votes cast by holders of ordinary shares and preference shares, voting as one class, at the special general meeting in accordance with Aspen’s bye-laws.

Voting Securities (Page 104)

Except as provided below (i) holders of ordinary shares have one vote for each ordinary share held by them and are entitled to vote on all the proposals voted on at the special general meeting or any adjournment thereof and (ii) holders of preference shares have one vote for each preference share held by them and are entitled to vote only on the merger proposal and on the adjournment proposal. See the section of this proxy statement titled “The Special General Meeting—Voting Securities” beginning on page 104 for a description of the voting rights of the preference shares.

In accordance with Aspen’s bye-laws, if a U.S. shareholder is deemed to control more than 9.5% of the aggregate voting power of shares of Aspen entitled to vote, the votes conferred by the controlled shares are reduced by whatever amount is necessary so that after such reduction the votes conferred by the controlled shares of such shareholder will represent 9.5% of the aggregate voting power of shares of Aspen entitled to vote.

If your ordinary shares or preference shares are held in “street name” by your bank, broker or other nominee, you should instruct your bank, broker or other nominee how to vote your shares using the instructions provided by your bank, broker or other nominee.

If you fail to submit a proxy or to vote in person at the special general meeting and you are a record holder, your shares will not be counted for purposes of quorum or as votes cast at the special general meeting. If your ordinary shares or preference shares are held in “street name” and you do not provide your bank, broker or other nominee with voting instructions, your shares will be treated as “broker non-votes” as described below. If you choose to vote in person at the special general meeting and your ordinary shares or preference shares are held in “street name”, you must first obtain a legal proxy form from your broker, bank or other nominee and bring such executed form with you to the meeting.

Abstentions and “Broker Non-Votes” (Page 105)

Abstentions and “broker non-votes” will be counted toward the presence of a quorum at the special general meeting, but will not be considered votes cast on any proposal brought before the special general meeting. Given

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the vote required to approve the proposals to be voted upon at the special general meeting (other than the bye-law amendment proposal and, if the bye-law amendment proposal is not approved, the merger proposal) is the affirmative vote of the specified required percentage of the votes cast assuming a quorum is present, an abstention or a “broker non-vote” with respect to any proposal to be voted on at the special general meeting (other than the bye-law amendment proposal and, if the bye-law amendment proposal is not approved, the merger proposal) will not have the effect of a vote for or against the relevant proposal, but will reduce the number of votes cast and therefore increase the relative influence of those shareholders voting. With respect to the bye-law amendment proposal, approval of which requires the affirmative vote of holders of at least 66% of the voting power of ordinary shares, abstentions and “broker non-votes” will have the effect of a vote “against” the bye-law amendment proposal. With respect to the merger proposal, which, if the bye-law amendment proposal is not approved, requires the affirmative vote of holders of at least 66% of the voting power of ordinary shares and preference shares, abstentions and “broker non-votes” will have the effect of a vote “against” the merger proposal.

Revocation of Proxies (Page 105)

You may revoke a submitted proxy prior to its exercise by either giving notice of such revocation to the General Counsel of Aspen in writing at Aspen Insurance Holdings Limited, 141 Front Street, Hamilton HM19, Bermuda, or attending and voting in person at the special general meeting or by executing a subsequent proxy, provided that such action is taken in sufficient time to permit the necessary examination and tabulation of the subsequent proxy or revocation before the votes are taken.

If your ordinary shares or preference shares are held in “street name” by your bank, broker or other nominee, please follow the instructions provided by your bank, broker or other nominee as to how to revoke your previously provided voting instructions.

Background of the Merger (Page 24)

A description of the actions that led to the execution of the merger agreement is included under the section of this proxy statement titled “The Merger — Background of the Merger.”

Recommendation of the Board of Directors (Page 35)

The Board has unanimously, by all directors present at a duly called meeting, adopted resolutions whereby it has (1) determined that the bye-law amendment is advisable and in the best interests of Aspen, and authorized and approved the bye-law amendment, (2) determined that the merger consideration constitutes no less than fair value for each ordinary share in accordance with the Companies Act, that the preference shares of the surviving company constitutes fair value for each of the preference shares of Aspen in accordance with the Companies Act and that the merger, on the terms and subject to the conditions set forth in the merger agreement and the statutory merger agreement, is fair to, and in the best interests of, Aspen and its shareholders, (3) approved the merger, the merger agreement and the statutory merger agreement, and (4) resolved to recommend approval of the bye-law amendment, the merger, the merger agreement, and the statutory merger agreement to Aspen’s shareholders for their consideration at the special general meeting. Accordingly, the Board recommends that Aspen’s shareholders vote “FOR” the bye-law amendment proposal, “FOR” the merger proposal, “FOR” the compensation advisory proposal and “FOR” the other proposals described in this proxy statement in respect of which they are entitled to vote. See the section of this proxy statement titled “The Merger—Reasons for the Merger; Recommendation of Aspen’s Board of Directors; Fairness of the Merger” beginning on page 35 for the factors considered by the Board in reaching its determination that the merger, on the terms and subject to the conditions set forth in the merger agreement, is fair to, and in the best interests of, Aspen and its shareholders.

Opinion of Goldman Sachs (Page 40)

Goldman Sachs & Co LLC (“Goldman Sachs”) rendered its oral opinion to the Board, which opinion was subsequently confirmed in a written opinion dated August 27, 2018, that, as of the date of such opinion and based

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upon and subject to the factors and assumptions set forth therein, the $42.75 in cash per ordinary share to be paid to the holders (other than Parent and its affiliates) of ordinary shares pursuant to the merger agreement was fair from a financial point of view to such holders.

The full text of the written opinion of Goldman Sachs, dated August 27, 2018, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex B to this proxy statement. Goldman Sachs provided advisory services and its opinion for the information and assistance of the Board in connection with the consideration of the merger. The Goldman Sachs opinion is not a recommendation as to how any holder of Aspen’s ordinary shares should vote with respect to the merger, or any other matter.

For more information, see the section entitled “The Merger— Opinion of Aspen’s Financial Advisor (Goldman Sachs)” on page 40 of this proxy statement and Annex B to this proxy statement.

Opinion of J.P. Morgan Securities LLC (Page 43)

At the meeting of the Board on August 27, 2018, J.P. Morgan Securities LLC (“J.P. Morgan”) rendered its oral opinion to the Board, which opinion was subsequently confirmed in a written opinion dated August 27, 2018, that, as of the date of such opinion and based upon and subject to the factors and assumptions set forth therein, the $42.75 in cash per ordinary share to be paid to the holders of ordinary shares pursuant to the merger agreement was fair from a financial point of view to such holders.

The full text of the written opinion of J.P. Morgan, dated August 27, 2018, which sets forth the assumptions made, matters considered and limits on the review undertaken, is attached as Annex C to this proxy statement and is incorporated herein by reference. Aspen’s shareholders are urged to read the opinion in its entirety. J.P. Morgan’s written opinion is addressed to the Board, is directed only to the consideration to be paid in the merger and does not constitute a recommendation to any shareholder of Aspen as to how such shareholder should vote at the special general meeting. The summary of the opinion of J.P. Morgan set forth in this proxy statement is qualified in its entirety by reference to the full text of such opinion.

For more information, see the section entitled “The Merger—Opinion of Aspen’s Financial Advisor (J.P. Morgan)” on page 43 of this proxy statement and Annex C to this proxy statement.

Financing (Page 53)

The consummation of the merger is not conditioned upon receipt of financing by Parent. Parent has obtained equity financing commitments for the transactions contemplated by the merger agreement, the aggregate proceeds of which will be used to pay the merger consideration. Apollo Investment Fund IX, L.P., Apollo Overseas Partners (Delaware 892) IX, L.P., Apollo Overseas Partners (Delaware) IX, L.P., Apollo Overseas Partners (Lux) IX, SCSp and Apollo Overseas Partners IX, L.P. (collectively the “Apollo Funds”) entered into an equity commitment letter, dated August 27, 2018 (the “equity commitment letter”), pursuant to which the Apollo Funds committed to purchase, or cause to be purchased, equity of Parent for an aggregate amount of up to approximately $2.6 billion.

Pursuant to the merger agreement, Parent and Merger Sub have represented that, assuming the equity financing is funded in accordance with the equity commitment letter, at the closing of the merger, Parent will have sufficient funds to pay the merger consideration and all other amounts required to be paid by Parent at the closing of the merger under the merger agreement, and all related fees and expenses required to be paid at the closing of the merger by Parent in connection with the transactions contemplated by the merger agreement.

Limited Guarantee

Concurrently with the execution of the merger agreement, and as a condition and inducement to Aspen’s willingness to enter into the merger agreement, Parent and Merger Sub delivered to Aspen a limited guarantee

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(the “limited guarantee”) in favor of Aspen by the Apollo Funds pursuant to which, and subject to the terms and conditions contained therein, the Apollo Funds are guaranteeing certain obligations of Parent and Merger Sub in connection with the merger agreement. The Apollo Funds’ obligations under the limited guarantee are subject to a maximum aggregate cap of $167,370,000.

Interests of Aspen’s Directors and Executive Officers in the Merger (Page 54)

Aspen’s executive officers and directors may have interests in the merger that may be different from, or in addition to, those of Aspen’s shareholders generally. The Board was aware of and considered these interests to the extent such interests existed at the time, among other matters, in evaluating and negotiating the merger agreement, in approving the merger agreement and the merger and in recommending that the merger agreement be approved by the shareholders of Aspen. Such interests potentially include entitlement to:

See the section of this proxy statement titled “The Merger—Interests of Aspen’s Directors and Executive Officers in the Merger” beginning on page 54 for a more detailed discussion on the interests of Aspen’s directors and executive officers in the merger.

The Merger Agreement (Page 64)

Treatment of Ordinary Shares (Page 64)

At the effective time, each ordinary share issued and outstanding immediately prior to the effective time (other than ordinary shares owned by Aspen as treasury shares, owned by any subsidiary of Aspen or owned by Parent, Merger Sub or any subsidiary of Parent, which will be canceled as set forth in the merger agreement) will be canceled and converted into the right to receive the merger consideration of $42.75 per ordinary share in cash, without interest and less any required withholding taxes.

Treatment of Preference Shares (Page 75)

At the effective time, each 5.95% preference share and 5.625% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged.

Treatment of Aspen Equity Awards (Page 76)

Performance Units. Each restricted share unit granted under Aspen’s 2003 Share Incentive Plan, 2013 Share Incentive Plan or 2016 Stock Incentive Plan for Non-Employee Directors, each as amended (collectively, the “company share plans”), that is subject to performance-based vesting requirements (“performance unit”), that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of performance units outstanding immediately prior to the effective time, (i) with respect to any portion of a

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performance unit award with a performance period that has been completed, the number of shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a performance unit award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

Phantom Shares. Each phantom share granted under a company share plan that is subject to performance-based vesting requirements (“phantom share”) that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of phantom shares outstanding immediately prior to the effective time, (i) with respect to any portion of a phantom share award with a performance period that has been completed, the number of phantom shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a phantom share award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

RSU Awards. Each restricted share unit award granted under a company share plan (“RSU”) that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to (i) the sum of (x) the merger consideration and (y) any accrued but unpaid dividend equivalents in respect of such RSU, multiplied by (ii) the number of ordinary shares subject to such RSU which had not previously been settled, less any applicable tax withholdings.

Treatment of Aspen ESPP (Page 77)

Aspen will take all actions necessary to cause its Employee Share Purchase Plan, 2008 Sharesave Scheme and International Employee Share Purchase Plan (collectively, the “Aspen ESPP”) (i) not to commence an offering period to purchase ordinary shares that would otherwise begin after the end of any offering period in effect as of the date of the merger agreement, (ii) not to accept payroll deductions to be used to purchase ordinary shares under the Aspen ESPP after the end of any offering period in effect as of the date of the merger agreement and (iii) to ensure that no new participants be permitted to participate in the Aspen ESPP and that the existing participants thereunder may not increase their elections with respect to any offering period in effect as of the date of the merger agreement. In addition, Aspen will take all actions necessary to cause the Aspen ESPP to terminate immediately after the purchases set forth in the following paragraph, if any, are completed and immediately prior to the effective time.

In the case of any outstanding purchase rights under the Aspen ESPP, (i) immediately prior to the effective time (x) any offering period under Aspen’s Employee Share Purchase Plan and the International Employee Share Purchase Plan will end and each participant’s accumulated payroll deduction will be used to purchase newly issued ordinary shares in accordance with the terms of Aspen’s Employee Share Purchase Plan or the International Employee Share Purchase Plan (as applicable) and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement, and (ii) prior to the effective time (x) Aspen will promptly take all actions necessary to enable and require participants in its 2008 Sharesave Scheme to utilize their accumulated payroll deduction to purchase newly issued ordinary shares in accordance with the terms of the 2008 Sharesave Scheme, such that there are no outstanding purchase rights thereunder as of the effective time and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement.

Regulatory Clearances Required for the Merger (Page 60)

Under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, Aspen and Parent cannot consummate the merger until Aspen and Parent have notified the Department of Justice’s Antitrust Division and the Federal

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Trade Commission of the merger and furnished them with certain information and materials relating to the merger and the applicable waiting period has terminated or expired. On September 25, 2018, Aspen and Parent filed their respective Notification and Report Forms, and early termination of the waiting period was granted effective October 2, 2018.

Under the EU Merger Regulation, the merger cannot be consummated until after the European Commission has issued its clearance decision.

Under the Chilean Protection of Free Competition Act, the merger cannot be consummated until after the Chilean Competition Authority has issued its clearance decision.

Pursuant to the Turkish Law on Protection of Competition No. 4054 dated 13 December 1994, the merger cannot be consummated until after the Turkish Competition Board has issued its clearance decision or the relevant waiting periods have expired without the issuance of a decision.

Under the South African Competition Act 89 of 1998, as amended, the merger cannot be consummated until after the South African Competition Authority has issued its clearance decision or the relevant waiting periods have expired without the issuance of a decision.

Further conditions include the receipt of other required regulatory approvals, including from the North Dakota Insurance Department, the Texas Department of Insurance, the Bermuda Monetary Authority, the UK Prudential Regulation Authority, the UK Financial Conduct Authority, Lloyd’s of London, the Australian Treasury, the Jersey Financial Services Commission, the Dubai Financial Services Authority, the Central Bank of Ireland, and the Italian Institute for the Supervision of Insurance.

No Solicitation of Takeover Proposals; Adverse Recommendation Change; Alternative Acquisition Agreements (Page 71)

Aspen has agreed in the merger agreement that it will not, and will cause each of its subsidiaries, and its and their respective directors, officers and employees not to, and will use its reasonable best efforts to cause its other representatives not to, among other things, solicit, knowingly encourage, initiate or take any action to facilitate or engage in or otherwise participate in any discussions or negotiations regarding the submission of any inquiry or the making of any proposal, in each case that constitutes, or would reasonably be expected to lead to, a “takeover proposal” (as described and summarized on page 71 of this proxy statement).

If Aspen receives a bona fide written takeover proposal during the period between August 27, 2018 and the date Aspen’s shareholders approve the merger agreement where such takeover proposal did not result from a material breach by Aspen of the non-solicitation or related provisions of the merger agreement, and the Board determines in good faith, after consultation with its financial advisors and outside legal counsel, that such takeover proposal constitutes or would reasonably be expected to lead to a “superior proposal,” then Aspen may, subject to certain conditions, enter into a confidentiality agreement with and furnish information (including non-public information) about Aspen and its subsidiaries to the person or group of persons making the takeover proposal and engage in or otherwise participate in discussions or negotiations with the person or group of persons making such takeover proposal.

The Board has agreed to recommend approval of the merger proposal and the bye-law amendment proposal at the special general meeting and that it will not change such recommendation, except in certain circumstances described below.

The Board may make an “adverse recommendation change” (as described and summarized on page 73 of this proxy statement) in compliance with the terms of the merger agreement prior to the time the approval of Aspen’s shareholders of the merger proposal is obtained, if the Board determines in good faith, after consultation with its financial advisors and outside legal counsel, that failure to take such action would be inconsistent with the directors’ fiduciary duties under applicable law in response to either (i) a “superior proposal” (as described

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and summarized on page 74 of this proxy statement) received by Aspen or (ii) an “intervening event” (as described and summarized on page 75 of this proxy statement). If Aspen makes an adverse recommendation change, Parent may terminate the agreement and Aspen will be required to pay Parent a termination fee of $82,935,000.

Subject to the procedures set forth in the merger agreement, if Aspen receives a superior proposal, Aspen may terminate the merger agreement prior to obtaining shareholder approval of the merger proposal to enter into an alternative acquisition agreement in respect of such superior proposal if the Board determines in good faith, after consultation with its financial advisors and outside legal counsel, that failure to take such action would be inconsistent with the directors’ fiduciary duties under applicable law. In such case, Aspen will be required to pay Parent a termination fee of $82,935,000.

Conditions to the Merger (Page 66)

Mutual Conditions

The obligations of Aspen, Parent and Merger Sub to consummate the merger under the merger agreement are subject to the satisfaction (or waiver by the applicable parties, if permissible under applicable law) of the following conditions:

Parent and Merger Sub Conditions

Parent and Merger Sub’s obligations to consummate the merger are subject to the satisfaction (or waiver by Parent and Merger Sub, if permissible under applicable law) of the following additional conditions:

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See the section of this proxy statement titled “The Merger Agreement—Conditions to Completion of the Merger” beginning on page 66 for more information on the conditions to the parties’ respective obligations to consummate the merger.

Termination of the Merger Agreement (Page 80)

The merger agreement may be terminated at any time before the effective time by mutual written consent of Aspen and Parent and, subject to certain limitations described in the merger agreement, by either Parent or Aspen if any of the following occurs:

The merger agreement may be terminated by Parent if any of the following occurs:

See the section of this proxy statement titled “The Merger Agreement—Termination of the Merger Agreement” for more information on the respective termination rights of the parties under the merger agreement.

Expenses and Termination Fees (Page 84)

Generally, all fees and expenses incurred in connection with the merger agreement and the transactions contemplated by the merger agreement and the statutory merger agreement will be paid by the party incurring or required to incur such fees and expenses, whether or not the merger is consummated.

Subject to the procedures set forth in the merger agreement, if Aspen receives a superior proposal and Aspen’s shareholders have not yet approved the merger proposal, Aspen may terminate the merger agreement to enter into an alternative acquisition agreement in respect of such superior proposal, if the Board determines in

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good faith, after consultation with its financial advisors and outside legal counsel, that failure to take such action would be inconsistent with the directors’ fiduciary duties under applicable law. In such case Aspen must pay Parent a termination fee of $82,935,000.

In addition, the merger agreement may be terminated by the Company, and Parent must pay the Company a reverse termination fee of $165,870,000, if, any of the following occurs:

See the section of this proxy statement titled “The Merger Agreement—Expenses and Termination Fees” for more information on the respective termination fees payable in certain circumstances by the parties under the merger agreement.

Market Price of Aspen Ordinary Shares (Page 96)

The closing price of the ordinary shares on the New York Stock Exchange (the “NYSE”) on August 27, 2018, the last full trading day prior to the announcement of the transaction, was $40.10 per ordinary share. On November 5, 2018, the most recent practicable date before this proxy statement was mailed to our shareholders, the closing price of ordinary shares on the NYSE was $42.00 per ordinary share. You are encouraged to obtain current market quotations for ordinary shares prior to voting your ordinary shares.

Dissenting Shares (Page 75)

Under Bermuda law, Aspen’s shareholders have rights of appraisal, pursuant to which those shareholders of Aspen who do not vote in favor of the merger proposal and who are not satisfied that they have been offered fair value for their shares will be permitted to apply to the Bermuda Court for an appraisal of the fair value of their shares within one month after the notice convening the special general meeting is given and otherwise fully comply with the requirements for seeking appraisal under the Companies Act. See the sections of this proxy statement titled “The Merger—Dissenters’ Rights of Appraisal for Aspen Shareholders” beginning on page 63 and “The Merger Agreement—Dissenting Shares” beginning on page  75 for a more detailed description of the appraisal rights available to Aspen’s shareholders.

Delisting and Deregistration of Aspen Shares (Page 62)

If the merger is completed, the ordinary shares will be delisted from the NYSE and the Bermuda Stock Exchange (the “BSX”) and deregistered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

At the effective time, each preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged. The preference shares will remain listed on the NYSE and registered by Aspen under the Exchange Act immediately after the merger. Parent may decide, following the merger, to delist the preference shares from the NYSE, deregister such preference shares under the Exchange Act or take other action with respect to the preference shares.

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Material U.S. Federal Income Tax Consequences of the Merger (Page 111)

The exchange of ordinary shares for the merger consideration pursuant to the merger agreement generally will be a taxable transaction to U.S. holders (as defined below) of ordinary shares for U.S. federal income tax purposes. On an exchange of your ordinary shares for the merger consideration, you will generally recognize gain or loss for U.S. federal income tax purposes in an amount equal to the difference, if any, between the amount of cash received by you in the merger and your adjusted tax basis in your ordinary shares.

The continuation of preference shares as preference shares of the surviving company in the merger will not be a taxable event for U.S. federal income tax purposes for holders of preference shares. If you are a holder of preference shares, you will not recognize any income, gain or loss for U.S. federal income tax purposes upon the continuation of your preference shares as preference shares of Aspen as the surviving company in the merger, and will retain an adjusted tax basis and holding period in your surviving company preference shares equal to the adjusted tax basis and holding period you had in your preference shares prior to the merger.

TAX MATTERS ARE COMPLICATED AND THE TAX CONSEQUENCES OF THE MERGER TO YOU WILL DEPEND UPON THE FACTS OF YOUR PARTICULAR SITUATION. GIVEN INDIVIDUAL CIRCUMSTANCES MAY DIFFER, ASPEN STRONGLY URGES YOU TO CONSULT WITH YOUR TAX ADVISOR AS TO THE SPECIFIC TAX CONSEQUENCES OF THE MERGER TO YOU, INCLUDING THE APPLICABILITY OF U.S. FEDERAL, STATE, LOCAL, NON-U.S. AND OTHER TAX LAWS.

Proposed Amendment to Bye-Law (Page 107)

Aspen is asking its ordinary shareholders to approve an amendment to the Aspen bye-laws to reduce the shareholder vote required to approve a merger with any third party from the affirmative vote of at least 66% of the voting power of the shares entitled to vote at a meeting of the shareholders to a simple majority of the votes cast at a meeting of the shareholders.

The Board has unanimously, by all directors present at a duly called meeting, adopted resolutions whereby it has (1) determined that the bye-law amendment is advisable and in the best interests of Aspen, and authorized and approved the bye-law amendment and (2) resolved to recommend approval of the bye-law amendment proposal to Aspen’s shareholders for their consideration at the special general meeting.

Only ordinary shares issued and outstanding as of the record date may vote on the bye-law amendment proposal. Preference shares do not have a right to vote on the bye-law amendment proposal. The approval of the bye-law amendment proposal requires the affirmative vote of holders of at least 66% of the voting power of ordinary shares in accordance with Aspen’s bye-laws.

Approval of the bye-law amendment proposal is not a condition to consummation of the merger, but will have the effect of lowering the approval threshold for the merger proposal.

See the section of this proxy statement titled “Proposal 1—Approval of the Bye-Law Amendment Proposal” for more information on the bye-law amendment proposal.

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QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE SPECIAL GENERAL MEETING

The following questions and answers address some questions you may have regarding the special general meeting, the merger agreement and the merger. These questions and answers may not address all questions that may be important to you as a shareholder of Aspen. Please refer to the more detailed information contained elsewhere in this proxy statement, the annexes to this proxy statement and the documents referred to or incorporated by reference in this proxy statement for further information.

In order to consummate the merger, Aspen’s shareholders must approve the merger proposal. Aspen will hold the special general meeting to obtain approval of the merger proposal and to consider certain other related matters which are not prerequisites to the consummation of the merger. This proxy statement, which you should read carefully, contains important information about the merger and related transactions and other matters being considered at the special general meeting.

Ordinary shares outstanding as of the record date will be entitled to vote on each of the above proposals. Preference shares outstanding as of the record date will have the right to vote only on Proposal 2 and Proposal 4.

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See the section of this proxy statement titled “The Merger—Reasons for the Merger; Recommendation of Aspen’s Board of Directors; Fairness of the Merger” beginning on page 35 for a more complete description of the recommendations of the Board. In considering the recommendations of the Board, you should be aware that Aspen’s executive officers and directors may have interests in the merger that are different from, or in addition to, those of Aspen’s shareholders generally. See the section of this proxy statement titled “The Merger—Interests of Aspen’s Directors and Executive Officers in the Merger” beginning on page 54.

See the section of this proxy statement titled “The Merger Agreement—Conditions to Completion of the Merger” for more information.

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YOU SHOULD READ THE SECTION OF THIS PROXY STATEMENT TITLED “MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES” FOR A MORE DETAILED DISCUSSION OF THE U.S. FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER. TAX MATTERS ARE COMPLICATED AND THE TAX CONSEQUENCES OF THE MERGER TO YOU WILL DEPEND UPON THE FACTS OF YOUR PARTICULAR SITUATION. GIVEN INDIVIDUAL CIRCUMSTANCES MAY DIFFER, ASPEN STRONGLY URGES YOU TO CONSULT WITH YOUR TAX ADVISOR AS TO THE SPECIFIC TAX CONSEQUENCES OF THE MERGER TO YOU, INCLUDING THE APPLICABILITY OF U.S. FEDERAL, STATE, LOCAL, NON-U.S. AND OTHER TAX LAWS.

YOU SHOULD READ THE SECTION OF THIS PROXY STATEMENT TITLED “MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES” FOR A MORE DETAILED DISCUSSION OF THE U.S. FEDERAL INCOME TAX CONSEQUENCES OF THE MERGER. TAX MATTERS ARE COMPLICATED AND THE TAX CONSEQUENCES OF THE MERGER TO YOU WILL DEPEND UPON THE FACTS OF YOUR PARTICULAR SITUATION. BECAUSE INDIVIDUAL CIRCUMSTANCES MAY DIFFER, ASPEN STRONGLY URGES YOU TO CONSULT WITH YOUR TAX ADVISOR AS TO THE SPECIFIC TAX CONSEQUENCES OF THE MERGER TO YOU, INCLUDING THE APPLICABILITY OF U.S. FEDERAL, STATE, LOCAL, NON-U.S. AND OTHER TAX LAWS.

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See the section of this proxy statement titled “The Merger—Interests of Aspen’s Directors and Executive Officers in the Merger” beginning on page 54 for a more detailed discussion on the interests of Aspen’s directors and executive officers in the merger.

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See the section of this proxy statement titled “The Merger Agreement—Treatment of Aspen Equity Awards” beginning on page 76 for a more detailed discussion on the treatment of Aspen equity awards in the merger.

In the case of any outstanding purchase rights under the Aspen ESPP, (i) immediately prior to the effective time (x) any offering period under Aspen’s Employee Share Purchase Plan and the International Employee Share Purchase Plan will end and each participant’s accumulated payroll deduction will be used to purchase newly issued ordinary shares in accordance with the terms of Aspen’s Employee Share Purchase Plan or the International Employee Share Purchase Plan (as applicable) and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement, and (ii) prior to the effective time (x) Aspen will promptly take all actions necessary to enable and require participants in its 2008 Sharesave Scheme to utilize their accumulated payroll deduction to purchase newly issued ordinary shares in accordance with the terms of the 2008 Sharesave Scheme, such that there are no outstanding purchase rights thereunder as of the effective time and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement.

See the section of this proxy statement titled “The Merger Agreement—Treatment of Aspen ESPP” beginning on page 77 for a more detailed discussion on the treatment of Aspen ESPP rights in the merger.

If the bye-law amendment proposal is approved, the bye-law amendment will be effective immediately and prior to the vote on the merger proposal, so that the approval of the merger proposal will require the affirmative vote of a majority of the votes cast by holders of ordinary shares and preference shares, voting as one class, at the special general meeting or any adjournment thereof in accordance with Aspen’s bye-laws. If the bye-law amendment proposal is not approved, the approval of the merger proposal will

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require the affirmative vote of 66% of the voting power of ordinary shares and preference shares entitled to vote, voting as one class, at the special general meeting or any adjournment thereof in accordance with Aspen’s bye-laws.

The approval of the compensation advisory proposal requires the affirmative vote of a majority of the votes cast by holders of ordinary shares at the special general meeting in accordance with Aspen’s bye-laws. Holders of preference shares do not have the right to vote on the compensation advisory proposal.

The approval of the adjournment proposal requires the affirmative vote of a majority of the votes cast by holders of ordinary shares and preference shares, voting as one class, at the special general meeting in accordance with Aspen’s bye-laws.

See the section of this proxy statement titled “Questions and Answers About the Merger and the Special General Meeting—Who is entitled to vote at the special general meeting?” for a more detailed description.

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Beneficial Owner of Shares Held in Street Name. If your Aspen shares are held in the name of a bank, broker or other similar organization or nominee, then you are considered a beneficial owner of such Aspen shares held for you in what is known as “street name.” Most of Aspen’s shareholders hold their shares in “street name.” If this is the case, this proxy statement has been forwarded to you by your bank, broker or other organization or nominee together with a voting instruction form. You may vote by signing, dating and returning your voting instruction form to your broker. Please review the voting instruction form to see if you are able to submit your voting instructions by telephone or over the Internet. The organization or nominee holding your account is considered the shareholder of record for purposes of voting at the special general meeting. As a beneficial owner, you have the right to instruct the organization that holds your shares of record how to vote the Aspen shares that you beneficially own.

If your Aspen shares are held in “street name” by your bank, broker or other nominee, please follow the instructions provided by your bank, broker or other nominee as to how to revoke or change your previously provided voting instructions.

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Innisfree M&A Incorporated

501 Madison Avenue, 20th Floor

New York, New York 10022

Shareholders located in the United States and Canada may call toll-free: (888) 750-5834

Shareholders located in other jurisdictions may call: (412) 232-3651

Banks and Brokers may call collect: (212) 750-5833

If your broker, bank or other nominee holds your shares, you can also call your broker, bank or other nominee for additional information.

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CAUTIONARY STATEMENT CONCERNING FORWARD-LOOKING INFORMATION

Certain statements in this proxy statement are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and are made under the “safe harbor” provisions of The Private Securities Litigation Reform Act of 1995. In particular, statements using words such as “may,” “seek,” “will,” “likely,” “assume,” “estimate,” “expect,” “anticipate,” “intend,” “believe,” “do not believe,” “aim,” “predict,” “plan,” “project,” “continue,” “potential,” “guidance,” “objective,” “outlook,” “trends,” “future,” “could,” “would,” “should,” “target,” “on track” or their negatives or variations, and similar terminology and words of similar import, generally involve future or forward-looking statements. Forward-looking statements reflect Aspen’s current views, plans or expectations with respect to future events and financial performance. They are inherently subject to significant business, economic, competitive and other risks, uncertainties and contingencies. The inclusion of forward-looking statements herein should not be considered as a representation by Aspen or any other person that current plans or expectations will be achieved. The proposed merger is subject to risks and uncertainties and factors that could cause Aspen’s actual results to differ, possibly materially, from those in the specific projections, goals, assumptions and statements include, but are not limited to:

The foregoing review of important factors should not be construed as exhaustive and should be read in conjunction with the other cautionary statements that are included herein and elsewhere, including the risk factors included in Aspen’s most recent reports on Form 10-K and Form 10-Q and other documents of Aspen on file with or furnished to the SEC. Any forward-looking statements made in this proxy statement are qualified by these cautionary statements, and there can be no assurance that the actual results or developments anticipated by Aspen will be realized or, even if substantially realized, that they will have the expected consequences to, or effects on, Aspen or its business or operations. Except as required by law, Aspen undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise.

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THE PARTIES TO THE MERGER

Aspen Insurance Holdings Limited

Aspen, a Bermuda exempted company, provides reinsurance and insurance coverage to clients in various domestic and global markets through wholly-owned subsidiaries and offices in Australia, Bermuda, Canada, Ireland, Singapore, Switzerland, the United Arab Emirates, the United Kingdom and the United States. For the year ended December 31, 2017, Aspen reported $12.9 billion in total assets, $6.7 billion in gross reserves, $2.9 billion in total shareholders’ equity and $3.4 billion in gross written premiums. Its operating subsidiaries have been assigned a rating of “A” by Standard & Poor’s Financial Services LLC, an “A” (“Excellent”) by A.M. Best Company Inc. and an “A2” by Moody’s Investors Service, Inc.

For additional information on Aspen and its business, including how to obtain the documents that Aspen has filed with the SEC, see the section of this proxy statement titled “ Where You Can Find Additional Information.”

Highlands Holdings, Ltd.

Parent is a Bermuda exempted company and an affiliate of the Apollo Funds, which are each managed by affiliates of Apollo Management. Parent, Apollo Management and the Apollo Funds are affiliates of AGM. AGM is a leading global alternative investment manager with offices in New York, Los Angeles, Houston, Bethesda, London, Frankfurt, Madrid, Luxembourg, Mumbai, Delhi, Singapore, Hong Kong and Shanghai. AGM had assets under management of approximately $270 billion as of June 30, 2018 in private equity, credit and real estate funds invested across a core group of nine industries where AGM has considerable knowledge and resources. AGM’s units are listed on the NYSE under the symbol “APO”. Parent was formed solely for the purpose of engaging in the merger and other related transactions and to serve as the holding company of Merger Sub. Parent has not engaged in any business other than in connection with the merger and other related transactions.

Highlands Merger Sub, Ltd.

Merger Sub is a wholly-owned subsidiary of Parent that was formed by Parent solely for purposes of entering into the merger agreement and the statutory merger agreement and completing the transactions contemplated thereby. Upon completion of the merger, Merger Sub will be merged with and into Aspen and Merger Sub will cease to exist.

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THE MERGER

Effects of the Merger

On the terms and subject to the conditions of the merger agreement and the statutory merger agreement, and in accordance with the applicable provisions of the Companies Act, at the effective time, Merger Sub will merge with and into Aspen, the separate corporate existence of Merger Sub will cease and Aspen will survive the merger as a wholly-owned subsidiary of Parent. As a result of the merger under Bermuda law, Aspen’s and Merger Sub’s respective undertakings, property and liabilities will become vested in Aspen as the surviving company in the merger.

The merger agreement provides that, at the effective time, each ordinary share issued and outstanding immediately prior to the effective time (other than ordinary shares owned by Aspen as treasury shares, owned by any subsidiary of Aspen or owned by Parent, Merger Sub or any subsidiary of Parent, which will be canceled as set forth in the merger agreement) will be converted into the right to receive $42.75 in cash, without interest and less any required withholding tax. All such ordinary shares will no longer be outstanding and will be canceled and cease to exist and each holder of a certificate previously evidencing any ordinary shares or uncertificated ordinary shares represented by book-entry will cease to have any rights with respect to those shares, except the right to receive the merger consideration.

At the effective time, Parent will become the sole owner of Aspen’s ordinary shares. Therefore, Aspen’s current ordinary shareholders will cease to have direct or indirect ownership interests in Aspen or rights as Aspen ordinary shareholders, will not participate in any future earnings or growth of Aspen, will not benefit from any appreciation in value of Aspen and will not bear the future risks of Aspen’s operations.

At the effective time, each preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged.

Background of the Merger

The Board and Aspen’s senior management regularly review Aspen’s operations, financial condition, financial performance and long-term strategic plans and objectives, as well as industry and regulatory developments and their impact on Aspen’s long-term strategic plans and objectives, with the goal of maximizing shareholder value.

From time to time, representatives of other industry participants and private equity firms have contacted senior management of Aspen or members of the Board to gauge Aspen’s interest in potential business combination transactions, including a call in January 2018, from Mr. Gary Parr, Senior Managing Director of Apollo, to Mr. Christopher O’Kane, Aspen’s Group Chief Executive Officer.

At a meeting of the Board held on February 6 and 7, 2018, the Board discussed in detail Aspen’s strategic position in the marketplace, risks relating to Aspen’s ability to execute its long-term strategic plan as a stand-alone entity, potential alternatives to such long-term strategic plan, and the potential benefits of pursuing a sale of Aspen. Members of senior management and representatives of Aspen’s financial advisors, Goldman Sachs and J.P. Morgan, and its outside legal counsel, Willkie Farr & Gallagher LLP (“Willkie”), were also present at the meeting. The discussion covered the factors that had affected Aspen’s financial results for the year ended December 31, 2017, including Aspen’s underwriting and net losses during 2017, including as a result of the California wildfires that occurred in the fourth quarter of 2017 and other catastrophic events that occurred in 2017, attritional losses in its insurance segment, Aspen’s leverage and balance sheet, and its ratings outlook. The Board also reviewed and considered current and projected trends in the insurance and reinsurance industries,

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including the impact of continuing consolidation in the insurance and reinsurance industries, increasingly competitive pricing in many of the insurance and reinsurance markets in which Aspen operates, the continued growth of alternative capital and its impact on the reinsurance industry, the impact of tax reform in the United States and “Brexit” in the United Kingdom, and the potential impact of expected increases in U.S. interest rates. Mr. O’Kane provided an update to the Board regarding his communication with Mr. Parr.

The Board then considered a range of potential strategic alternatives with input from Aspen’s financial advisors and outside legal counsel, including whether to initiate a process to explore potential strategic alternatives, including a sale of Aspen, and whether and how to execute on Aspen’s long-term strategic plan, including whether and how to raise additional capital, if the need arose. The Board determined that, while it had not decided to sell the Company, it was advisable to explore a potential sale of Aspen as part of an overall review of strategic options, and authorized Aspen’s management to review potential sale options with the assistance of Goldman Sachs and J.P. Morgan.

On February 21, 2018, a member of the board of directors of Party A, a company that operates in the insurance and reinsurance industries, called Mr. Bret Pearlman, a member of the Board with whom the member of the board of directors of Party A was acquainted, to discuss the potential for a stock-for-stock business combination transaction between Aspen and Party A and to propose that representatives of Aspen meet with representatives of Party A to discuss the possibility of such a transaction. Following the call, Mr. Pearlman provided an update to Mr. Glyn Jones, Chairman of the Board, and Aspen’s financial advisors regarding the outreach from the Party A director.

At a meeting of the Board held on March 8, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, the Board again reviewed the potential options the Board was considering, including a potential sale of Aspen and the execution of Aspen’s long-term strategic plan, and the merits and risks associated with each of the options. Representatives of Aspen’s financial advisors reviewed with the directors Aspen’s financial performance and certain preliminary financial analyses performed by Aspen’s financial advisors. The discussion also covered an initial draft of the confidential information memorandum and projections prepared by Aspen’s management included therein to be provided to potential buyers. At the request of the Board, the confidential information memorandum was prepared by Aspen’s management team with the assistance of Aspen’s financial advisors. It was noted during that discussion that management was in the process of updating its views regarding the projected financial performance of Aspen’s business through 2020, which updates were not expected to be completed in time for the distribution of the confidential information memorandum. At that meeting, in order to facilitate the timely consideration of potential strategic alternatives, the Board established a Strategy Committee consisting of Mr. Jones, Mr. O’Kane and Board members Messrs. Matthew Botein, Gary Gregg, Gordon Ireland and Bret Pearlman, with Mr. Jones serving as chair. The Board selected the members of the Strategy Committee because of their collective knowledge of Aspen and its business, their business acumen and their knowledge and experience in executing business transactions. The Board was aware that Mr. Pearlman had a business relationship with senior executives of Apollo. Mr. Pearlman is a manager at HRS 1776 Partners, an entity affiliated with HRS Management LLC, the family office of Joshua Harris, a senior managing director and co-founder of Apollo.

The Board authorized the Strategy Committee, among other things, to review and analyze proposals for Aspen to engage in strategic transactions, including a potential sale of Aspen until May 2, 2018, the date of the next regularly scheduled Board meeting; to discuss with management and Aspen’s advisors the strategy regarding any discussions or negotiations with potential buyers relating to any such potential transaction, and to oversee such discussions or negotiations; to agree on the nature and scope of any due diligence review to be undertaken by any potential buyer; and to make recommendations to the Board with respect to the foregoing. The Board also discussed with management and representatives of Aspen’s financial advisors the parties that may be interested in exploring a potential transaction with Aspen and the Board authorized Aspen’s management and advisors to engage in discussions with potential counterparties. The Board also authorized the appointment of Goldman Sachs and J.P. Morgan as Aspen’s financial advisors.

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Following this Board meeting and as requested by the Board, on March 9, 2018, Messrs. O’Kane and Pearlman met with the Chief Executive Officer and Chief Financial Officer of Party A and a member of its board of directors to discuss the possibility of a stock-for-stock business combination transaction between Aspen and Party A. The parties discussed their respective views on the insurance and reinsurance industries and the parties’ respective businesses and operations. Following the meeting, Messrs. O’Kane and Pearlman provided an update to Mr. Jones and Aspen’s financial advisors regarding their communications with Party A.

On March 12, 2018, Mr. O’Kane met with Messrs. Parr and Harris to discuss Apollo’s insurance business and the potential for an acquisition of Aspen. Following this meeting, Mr. O’Kane provided an update to Mr. Jones and Aspen’s financial advisors regarding his communication with Apollo.

At a telephonic Board meeting on March 21, 2018, at which members of Aspen’s senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present, members of Aspen’s senior management team and representatives of Aspen’s financial advisors provided an update on the latest draft of the confidential information memorandum. Messrs. O’Kane and Pearlman also updated the Board on their conversation with Party A and Mr. O’Kane updated the Board on his conversation with Apollo.

Throughout March 2018, as requested by the Board, representatives of Aspen’s financial advisors, on behalf of Aspen, contacted and engaged in discussions with 26 potential counterparties, including both strategic buyers and financial sponsors (and which included Apollo, Party A, Party B, and Party C, as described below) to gauge their interest in making a proposal to acquire Aspen. Such potential counterparties included, among others, the potential counterparties that the Board and Aspen’s financial advisors believed, based on their knowledge and experience of the market and the insurance and reinsurance industries, were most likely to be interested in a potential acquisition of Aspen. Nine counterparties (including Apollo, Party A, Party B, and Party C) ultimately entered into confidentiality agreements with Aspen in connection with the ongoing sale process. The remaining 17 potential counterparties indicated they were not interested in pursuing a transaction with Aspen. Each of the parties that entered into a confidentiality agreement with Aspen received a confidential information memorandum prepared by Aspen’s management team with the assistance of Goldman Sachs and J.P. Morgan, which described and included projections regarding Aspen’s business and operations, and information regarding Aspen’s insurance and reinsurance loss reserves. None of these confidentiality agreements currently restricts any potential counterparty from making a proposal to acquire Aspen.

On March 22, 2018, a member of the board of directors of Party A called Mr. Pearlman to indicate that, if Aspen was not interested in entering into a stock-for-stock business combination transaction involving Aspen and Party A, Party A could partner with a private equity firm to acquire Aspen for cash or a mix of cash and stock. Following the call, Mr. Pearlman provided an update to Mr. Jones and Aspen’s financial advisors regarding this communication from Party A.

On April 3, 2018, Aspen and Apollo executed a confidentiality agreement, which included a standstill provision that did not permit Apollo to make a formal proposal to acquire Aspen, unless specifically invited to do so by Aspen.

At a telephonic Board meeting on April 4, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, representatives of Aspen’s financial advisors provided an update on the outreach in connection with a potential sale transaction. Representatives of Aspen’s financial advisors noted that a few prospective bidders had indicated an interest in acquiring only Aspen’s reinsurance business and one prospective bidder had indicated an interest in acquiring only Aspen’s capital markets business. Mr. Pearlman also updated the Board on his conversation with Party A. Messrs. O’Kane and Kirk also updated the Board on matters relating to the execution of Aspen’s long-term strategic plan and the risks associated with the implementation of the plan.

On April 14, 2018, Aspen and Party B executed a confidentiality agreement, which included a standstill provision that did not permit Party B to make a formal proposal to acquire Aspen, unless specifically invited to do so by Aspen.

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On April 16, 2018, Aspen and Party A executed a confidentiality agreement, which included a standstill provision that did not permit Party A to make a formal proposal to acquire Aspen, unless specifically invited to do so by Aspen.

On April 18, 2018, Party C, one of the potential counterparties whom Aspen’s financial advisors contacted to gauge its interest in making a proposal to acquire Aspen, informed Aspen’s financial advisors that it had decided to withdraw from the process and not to submit a proposal to acquire Aspen.

The Board convened by telephone on April 24, 2018. Members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present by telephone. Representatives of Aspen’s financial advisors provided an update on conversations with the potential counterparties they contacted at the direction of the Board regarding a transaction involving Aspen and summarized the principal reasons potential counterparties gave for declining to engage in the process. They also updated the Board on the progress made by, and their discussions with, the potential counterparties that remained active in the process. Messrs. O’Kane and Kirk also updated the Board on matters relating to the execution of Aspen’s long-term strategic plan and the risks associated with the implementation of the plan.

On April 25, 2018, Mr. O’Kane met with the Chief Executive Officer of Party A and discussed Party A’s interest in making an offer to enter into a business combination with Aspen and Party A’s plans for Aspen’s business after any such acquisition.

On April 27, 2018, Apollo submitted to Aspen a non-binding proposal to acquire 100% of Aspen’s outstanding ordinary shares for $45.00-$47.00 per ordinary share in cash, which proposal indicated that Apollo had the ability to commit to providing 100% of the amount required to complete the transaction through equity financing arrangements.

On April 30, 2018, Party A submitted to Aspen a non-binding proposal to enter into a stock-for-stock business combination transaction with Aspen as a result of which Aspen’s current shareholders would retain a majority of the pro forma ownership of the combined company. Party A’s proposal suggested an implied valuation of Aspen that was disproportionately lower than the implied valuation of Party A because Party A would be valued using a significantly higher multiple to book value than the multiple to book value that be used to value Aspen in the transaction. Party A indicated that it was receptive to exploring the inclusion of a limited cash component as part of the consideration.

On April 30, 2018, Party B, a company that operates in the insurance and reinsurance industries, submitted a non-binding proposal to acquire 100% of Aspen’s outstanding ordinary shares for $38.00 per ordinary share in Party B common stock and a pre-closing dividend payable by Aspen to Aspen’s shareholders of $7.00 per ordinary share in cash.

The remaining parties that received the confidential information memorandum indicated they were not interested in pursuing a potential transaction with Aspen.

At a meeting of the Board held on May 1 and 2, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, representatives of Willkie reviewed with the Board its fiduciary duties in connection with its consideration of a potential sale of Aspen and the Board engaged in a discussion of such duties and the sale process. Willkie also discussed with the Board the expected material terms of any merger agreement involving Aspen and potential implications of any merger on Aspen’s outstanding preference shares. Representatives of Aspen’s financial advisors summarized the conversations they had to date with potential buyers of Aspen. The Board then discussed the preliminary proposals received from each of the three bidders (Apollo, Party A and Party B) and the risks inherent in the proposals made by each of the three bidders, including each potential bidder’s plans for Aspen following the closing and how those plans might impact the likelihood that each such bidder would ultimately be willing or able to execute its proposed transaction. The Board also discussed the need to perform reverse diligence on Party A and Party B, given that their proposals included a large stock component as consideration. Following

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discussion, the Board decided that each of Apollo, Party A and Party B should be invited into the second round of the potential sale process, whereby each of the three bidders would be invited to undertake a more detailed due diligence review of Aspen and submit a revised, definitive proposal to acquire Aspen on or prior to June 28, 2018. The Board also separately discussed, as an alternative to the transactions proposed by Apollo, Party A and Party B, a potential sale of Aspen’s reinsurance business and the significant execution risk, protracted timeline, and other risks and considerations inherent in pursuing such a sale. The Board also discussed management’s updated views regarding the projected financial performance of Aspen’s business through 2020 and the risks inherent in the execution of Aspen’s long-term strategic plan.

At that meeting of the Board, the Board also authorized the Strategy Committee to remain in place through August 1, 2018. The Board was reminded that Mr. Pearlman had a business relationship with senior executives of Apollo. At the time of this Board meeting, Apollo was one of the three remaining bidders interested in making a proposal to enter into a transaction involving Aspen. The Board also discussed management’s updated views regarding the projected financial performance of Aspen’s business through 2020 and the risks inherent in the execution of Aspen’s long-term strategic plan.

On May 11, 2018, Aspen granted to representatives of Apollo, Party A and Party B access to an electronic data room containing documents and information with respect to Aspen to facilitate the due diligence process.

Between May 11, 2018 and late June, 2018, representatives of each of Apollo, Party A and Party B conducted separate due diligence reviews of Aspen and its business. Aspen’s management team and financial advisors regularly responded to questions from each of the three bidders regarding Aspen’s business and the documents and information made available in the electronic data room.

On May 16 and 17, 2018, members of senior management held management presentations and discussions regarding a potential transaction with representatives of Party A. Representatives of Aspen’s financial advisors and outside legal counsel attended the meeting. Aspen’s senior management made presentations to Party A regarding Aspen’s business and operations, and representatives of Party A asked questions of Aspen’s senior management in connection with their due diligence review of Aspen. Representatives of Party A made presentations to Aspen’s senior management regarding Party A’s business and operations, and Aspen’s senior management asked questions of Party A’s representatives in connection with their due diligence review of Party A.

On May 21, 2018, members of senior management held management presentations and discussions regarding a potential transaction with representatives of Party B. Representatives of Aspen’s financial advisors and outside legal counsel attended the meeting. Aspen’s senior management made presentations to Party B regarding Aspen’s business and operations, and representatives of Party B asked questions of Aspen’s senior management in connection with their due diligence review of Aspen.

On May 23, 2018, members of senior management held management presentations and discussions regarding a potential transaction with representatives of Apollo. Representatives of Aspen’s financial advisors and outside legal counsel attended the meeting. Aspen’s senior management made presentations to Apollo regarding Aspen’s business and operations, and representatives of Apollo asked questions of Aspen’s senior management in connection with their due diligence review of Aspen.

On June 1, 2018, the member of the board of directors of Party A who was acquainted with Mr. Pearlman called Mr. Pearlman to convey Party A’s expectation that the management team of Party A would lead the combined entity following any potential stock-for-stock business combination of Aspen and Party A. Following the call, Mr. Pearlman provided an update to Mr. Jones and Aspen’s financial advisors regarding this communication from the Party A director.

On June 5, 2018, Party A gave representatives of Aspen access to an electronic data room containing documents and information with respect to Party A to facilitate Aspen’s due diligence review of Party A. Aspen’s management team and outside legal counsel engaged in a review of the documents and information made available by Party A.

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On June 7, 2018, Mr. O’Kane, at the request of Party B, had a call with the Chief Executive Officer of Party B during which they discussed their respective views on the insurance and reinsurance industries and the parties’ respective businesses and operations.

At a telephonic Board meeting on June 7, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, members of Aspen’s senior management presented to the Board management’s updated views regarding the projected financial performance of Aspen’s business through 2020 (see “The Merger—Certain Aspen Prospective Financial Information”). The updates to the projections were primarily driven by, among other matters, improved projected underwriting results as a result of current views on natural catastrophe losses, projected performance improvement in insurance underwriting, projected expense reductions, projected improvement in results (other than those relating to catastrophic events) in certain business lines, and the impact of the discontinuation of the international professional indemnity, marine hull and aviation insurance business lines at Lloyd’s of London due to their limited contribution and volatility and the views of Aspen’s senior management and the Board that they should be discontinued as part of Aspen’s long-term strategic plan. The Board asked management questions regarding the assumptions underlying such projections, and the Board engaged in a discussion of Aspen’s long-term strategic plan. Representatives of Aspen’s financial advisors provided the Board with an update on the potential sale transaction and noted that Apollo, Party A and Party B continued to express interest in pursuing a potential sale transaction.

During the evening of June 10, 2018, the updated projections were placed in the Aspen data room. Each of Apollo, Party A and Party B had access to such projections.

On June 12, 2018, members of Aspen’s senior management met with representatives of Party B. During that meeting, the parties discussed the parties’ respective business strategies, legal and management structure, and market position.

During the evening of June 12, 2018, initial drafts of merger agreements (reflecting different potential transaction structures) prepared by Willkie were placed in the Aspen data room. Each of Apollo, Party A and Party B had access to such initial drafts.

On June 14, 2018, Mr. O’Kane met with the Chief Executive Officer of Party A to discuss their respective businesses and Party A’s plans for Aspen’s business following any potential business combination transaction.

On June 18, 2018, members of the Board had dinner with members of the board of directors of Party B during which the parties discussed the parties’ respective businesses, the strategic rationale for a potential business combination transaction involving the two companies, the scale and fit of the parties’ respective businesses, and matters relating to the integration and optimization of the parties’ respective businesses.

On June 19 and 20, 2018, members of Aspen’s senior management met with representatives of Party A to discuss the parties’ respective businesses and Party A’s plans with respect to Aspen’s businesses after the closing of a potential business combination transaction involving the two companies.

On June 19, 2018, Party B gave representatives of Aspen access to an electronic data room containing documents and information with respect to Party B to facilitate Aspen’s due diligence review of Party B. Aspen’s management team and outside legal counsel engaged in a review of the documents and information made available by Party B.

Also on June 19, 2018, Mr. Botein, as a member of the Strategy Committee, discussed with a representative of Party A the potential merits and considerations of a potential business combination involving Aspen and Party A.

On June 20, 2018, members of senior management and a representative of Party A met and discussed Party A’s plans for Aspen’s businesses following the closing. Following the meeting, Mr. Botein and a representative of Party A discussed the possibility that any business combination transaction involving Party A and Aspen be effected through a “merger of equals” transaction in which both Party A and Aspen would be valued in a consistent manner and using the same multiple to book value.

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On June 21, 2018, Party A informed representatives of Aspen’s financial advisors that Party A had decided to withdraw from the process and not to submit a revised proposal to enter into a “merger of equals” transaction involving Aspen or make a proposal to acquire Aspen for cash, stock or a mixture of cash and stock. Party A stated that it might be willing to re-engage in the future on terms in line with its initial bid (i.e., a stock-for-stock business combination transaction as a result of which Aspen’s shareholders would own a majority of the post-closing equity securities of the combined company and where Party A would be valued using a significantly higher multiple to book value than the multiple used to value Aspen).

On June 26, 2018, Apollo’s legal counsel, Sidley Austin LLP (“Sidley”), and Party B’s legal counsel each submitted a revised draft of a merger agreement to Aspen. Apollo’s draft of the merger agreement included a note that Apollo desired to discuss with Aspen the inclusion of a mechanism in the merger agreement to protect Apollo in the event of drastic changes in the book value of Aspen between the signing of the merger agreement and the closing of the transaction.

On June 28, 2018, Apollo submitted a revised non-binding proposal to acquire 100% of Aspen’s outstanding ordinary shares for $44.00 to $45.00 per ordinary share in cash, which offer indicated that Apollo had the ability to commit to providing 100% of the amount required to complete the transaction through equity financing arrangements. In its offer letter, Apollo requested a period of exclusivity during which (i) Aspen would not negotiate or discuss a potential alternative transaction with any other party, (ii) Apollo would work to complete its due diligence review of Aspen and (iii) the parties would negotiate a definitive merger agreement.

Also on June 28, 2018, the chairman of the board of directors of Party C called Mr. John Cavoores, a member of the Board with whom the chairman of the board of directors of Party C was acquainted, and expressed an interest in re-entering the process and potentially submitting a proposal to acquire Aspen. Representatives of Party C’s financial advisors subsequently clarified to representatives of J.P. Morgan that Party C would need to complete significant due diligence prior to providing a preliminary indication of interest to acquire Aspen and that Party C did not have sufficient funding to propose an all-cash transaction. Party C requested, as a condition to its agreement to conduct due diligence in advance of making any proposal regarding a transaction with Aspen, that Aspen enter into an agreement to negotiate exclusively with Party C and not to negotiate or discuss potential transactions with anyone other than Party C.

On June 29, 2018, Party B informed Aspen’s financial advisors that it had decided to withdraw from the process and not to submit a revised offer to acquire Aspen.

On June 30, 2018, representatives of Aspen’s financial advisors, at the direction of the Strategy Committee, contacted representatives of Party C to inform them that Aspen was not inclined to enter into an exclusivity agreement with Party C at that time and requested that Party C provide a preliminary indication of its proposed valuation of Aspen.

Beginning in July, 2018, to mitigate any uncertainty regarding Aspen’s ability to execute its long-term strategic plan as a stand-alone entity, Aspen granted retention bonus letters to certain of its key employees, including the following executive officers: Mr. Cain; Mr. Cohen; Mr. Issavi; Mr. Kirk and Mr. Schick.

The Board convened by telephone on July 2, 2018. Members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present by telephone. Representatives of Aspen’s financial advisors provided the Board with an update on the potential sale transaction and discussed the key terms of Apollo’s proposal, including the reduction in the price range indicated to $44.00 to $45.00 per ordinary share (compared to Apollo’s initial indication of $45.00 to $47.00 per ordinary share in April 2018), Apollo’s request for a period of exclusivity, and Apollo’s desire to discuss a mechanism in the merger agreement to protect Apollo in the event of drastic changes in the book value of Aspen between the signing of the merger agreement and the closing. The Board discussed the reasons provided by Party A and Party B for declining to submit an offer and the conditions under which Party A indicated that it might be willing to re-engage in the

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process. The Board also discussed the call from Party C indicating an interest in potentially submitting a proposal after being granted exclusivity. After extensive discussion, the Board directed its financial advisors to request that Apollo provide a best and final price per share and to clarify the terms and conditions of its proposal by July 16, 2018. The Board also directed its financial advisors to contact Party C to further gauge the seriousness of Party C’s approach and assess the likelihood that Party C would have the interest and financial wherewithal to make a proposal to acquire Aspen that was more favorable to Aspen’s shareholders than Apollo’s proposal. Because the Board believed that the terms of the potential business combination involving Aspen and Party A being contemplated by Party A were not as attractive as the terms of Apollo’s proposal, the Board did not authorize Aspen’s management or financial advisors to request a revised proposal from Party A.

On July 2 and 3, 2018, representatives of Aspen’s financial advisors contacted representatives of each of Apollo and Party C to discuss the matters identified by the Board.

On a call among representatives of Goldman Sachs, J.P. Morgan and Apollo that took place during that time, representatives of Apollo indicated that Apollo’s willingness to engage in further confirmatory due diligence of Aspen was conditioned on Aspen’s willingness to enter into an exclusivity agreement with Apollo, and that Apollo would likely not be in a position to finalize and execute any potential merger agreement for another four to six weeks.

On a call among representatives of Aspen’s financial advisors and representatives of Party C that took place during that time, the representatives of Party C indicated that Party C would not be willing to engage in a due diligence review of Aspen, unless Aspen was willing to enter into an exclusivity agreement with Party C and that Aspen should not expect the merger consideration to be paid by Party C in any proposed transaction to exceed the then-current market price of Aspen’s shares. Party C likewise indicated that the merger consideration to be paid by Party C in any potential transaction would likely not consist solely of cash. Party C did not subsequently make any proposal or submit any preliminary indication of interest to acquire Aspen.

The Board convened by telephone on July 5, 2018. Members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present by telephone. Representatives of Aspen’s financial advisors provided the Board with an update on their discussions with Apollo and Party C. The Board and its advisors engaged in a discussion of the responses from Apollo and Party C. The Board and representatives of Willkie discussed the expected terms of any merger agreement with Apollo, including expected terms that would govern Aspen’s ability to engage with or accept alternative proposals to acquire Aspen should they be made by a third party following the execution of any merger agreement with Apollo, and regarding the standstill provisions in confidentiality agreements with potential counterparties, which would terminate upon execution of any merger agreement with Apollo and would not prohibit any third party who signed such a confidentiality agreement from making a proposal to acquire Aspen. After discussion, and considering the attractiveness of Apollo’s proposal and the fact that Apollo remained the only active bidder, the Board authorized management to negotiate an exclusivity agreement with Apollo.

On July 8, 2018, representatives of Willkie delivered a draft exclusivity agreement to representatives of Sidley. Between July 8 and July 10, 2018, Willkie and Sidley negotiated the terms of the exclusivity agreement on behalf of Aspen and Apollo, respectively.

At a telephonic Board meeting on July 10, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, the Board discussed in detail the revised proposal Apollo made on June 28, 2018, and the time and process Apollo indicated it would need to complete its due diligence review of Aspen. Following that discussion, the Board approved the entry by Aspen into the exclusivity agreement with Apollo.

On July 11, 2018, Apollo and Aspen entered into an exclusivity agreement. The exclusivity agreement provided that the exclusivity period thereunder would extend until the earlier of (i) August 8, 2018 and (ii) any time at which Apollo makes a material modification to the terms of its proposal. It also provided that Aspen

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could terminate the exclusivity agreement earlier, on July 28, 2018, if Apollo failed to provide a written proposal on or about July 27, 2018 indicating that the merger consideration proposed by Apollo remained within the per share price range set forth in its offer letter, dated June 28, 2018.

During the period from July 11, 2018 through July 30, 2018, Aspen and Apollo had frequent discussions and meetings as part of Apollo’s confirmatory due diligence process, and representatives of Willkie and Sidley discussed the proposed terms of the merger agreement.

On July 17, 2018, representatives of Willkie sent representatives of Sidley a revised draft of the merger agreement.

The Board convened by telephone on July 23, 2018. Members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present by telephone. Representatives of Goldman Sachs, J.P. Morgan and Willkie provided the Board with an update on their ongoing discussions with Apollo.

On July 27, 2018, Apollo confirmed its interest in acquiring Aspen for a price within the range of $44.00 to $45.00 per share and requested an extension of the exclusivity period under the exclusivity agreement through late August, 2018.

At a meeting of the Board held on July 30, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, representatives of Goldman Sachs, J.P. Morgan and Willkie provided the Board with an update on their ongoing discussions with Apollo, the progress of Apollo’s due diligence review of Aspen and the developing terms of the merger agreement with Apollo, including the provisions of the merger agreement related to the bye-law amendment. Representatives of each of Goldman Sachs and J.P. Morgan presented to the Board their preliminary financial analyses of the proposed merger consideration. The Board authorized management and Aspen’s financial advisors and outside legal counsel to negotiate an extension to the exclusivity agreement with Apollo. The Board also discussed potential alternatives to a sale of Aspen, including risks and considerations relating to the execution by Aspen of its long-term strategic plan.

At a meeting of the Board held on August 1, 2018, the Board authorized the Strategy Committee to remain in place through October 25, 2018 and Mr. Pearlman was appointed as chair of the Strategy Committee because Mr. Jones, the chair of the Strategy Committee, would be traveling and possibly unreachable at times during this period. On August 1, 2018, Apollo and Aspen entered into an amendment to the exclusivity agreement, which provided that Aspen could terminate exclusivity on August 8, 2018, unless Apollo provided a written proposal on or about August 7, 2018 indicating that the merger consideration proposed by Apollo remained within the per share price range set forth in its offer letter, dated June 28, 2018, in which case the exclusivity period would be extended to August 17, 2018.

Between August 1, 2018 and August 15, 2018, representatives of Aspen and Apollo held frequent discussions regarding matters relating to Apollo’s due diligence review of Aspen.

On August 3, 2018, representatives of Sidley sent representatives of Willkie a revised draft of the merger agreement.

On August 6, 2018, representatives of Aspen’s financial advisors, at the direction of Aspen’s management, contacted representatives of Apollo to discuss a change to Aspen’s senior management team that was scheduled to be announced on August 7, 2018. During that conversation, Apollo requested additional individual meetings with members of Aspen’s senior management team to discuss matters relating to Apollo, its track record and vision for investments in the insurance and reinsurance industries, Apollo’s due diligence review of Aspen and future plans for Aspen’s businesses.

On August 7, 2018, Aspen issued a press release to announce changes in the leadership of Aspen’s reinsurance business. Also on that date, representatives of Willkie and representatives of Sidley discussed by telephone issues arising out of the draft merger agreement.

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On August 8, 2018, Apollo communicated to representatives of Aspen’s financial advisors that it was not confirming its price, as contemplated by the amended exclusivity agreement, dated August 1, 2018, and that it would provide an update on its proposal after its investment committee meeting the following week.

During the period from August 8, 2018 through August 10, 2018, representatives of Apollo met individually with members of Aspen’s senior management team to discuss matters relating to Apollo, its track record and vision for investments in the insurance and reinsurance industries, Apollo’s due diligence review of Aspen and future prospects for Aspen’s businesses in light of market and industry conditions. Representatives of Aspen’s financial advisors or legal counsel were also present at such meetings.

On August 15, 2018, Apollo communicated to representatives of Aspen’s financial advisors a further revision to its offer to acquire 100% of Aspen’s outstanding ordinary shares. Under the revised terms of its proposal, Apollo would acquire 100% of Aspen’s outstanding ordinary shares for $41.00 per ordinary share in cash and the merger agreement would provide, among other things, that Apollo’s obligation to consummate the merger would be conditioned on the absence of a ratings downgrade of Aspen’s ratings by any of A.M. Best, S&P or Moody’s. In addition, Apollo’s revised proposal stated that it would have the ability to terminate the merger agreement at any time prior to closing if Aspen’s book value declined for any reason by 10% or more relative to its book value as of June 30, 2018. In connection with discussions regarding this proposal, representatives of Apollo communicated the need for these provisions at the valuation reflected in its proposal. Also on that date, representatives of Sidley sent representatives of Willkie an initial draft of an equity commitment letter and a limited guarantee.

At a telephonic Board meeting on August 17, 2018, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, the Board discussed Apollo’s further revised offer, including the price Apollo was offering to acquire Aspen and the terms of the merger agreement proposed by Apollo. Representatives of each of Goldman Sachs and J.P. Morgan presented to the Board their updated preliminary financial analyses of the proposed merger consideration. The Board also discussed alternative courses of action that the Board was prepared to take with respect to the implementation of Aspen’s long-term strategic plan if the Board did not move forward with a transaction. Finally, the Board discussed the parameters of the terms of a transaction with Apollo that the Board likely would find acceptable. At the end of the meeting, the Board instructed Aspen’s senior management team, financial advisors and outside legal counsel to work with the Strategy Committee to develop a proposal within the parameters discussed by the Board that would satisfy the Board’s requirements for such a transaction and negotiate with Apollo to determine whether the parties could agree to a transaction on acceptable terms. During the meeting, it was noted that Mr. Pearlman is a manager at HRS 1776 Partners, an entity affiliated with HRS Management LLC, the family office of Joshua Harris, a senior managing director and co-founder of Apollo. The Board did not believe that Mr. Pearlman’s relationship with Mr. Harris would affect his judgment concerning the Board’s consideration of a potential transaction involving Apollo. Given that Apollo had emerged as the final bidder with whom the Company was expected to negotiate potential transaction terms, and in an abundance of caution, following the Board meeting, Mr. Botein assumed the role of chair of the Strategy Committee.

On August 18, 2018, the Strategy Committee held a meeting, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present. At the meeting, the Strategy Committee discussed the terms of a potential counterproposal within the parameters discussed by the Board to be made by Aspen’s representatives to Apollo whereby Apollo would acquire 100% of Aspen’s outstanding ordinary shares for $42.75 per ordinary share in cash and the merger agreement would provide, among other things, that (i) there would not be any closing condition resulting from a downgrade of any rating of Aspen issued by Moody’s, (ii) the Board would have flexibility to take certain actions to avoid any potential ratings downgrade, notwithstanding the restrictive covenants to the contrary that were included in the draft merger agreement proposed by Apollo, and (iii) the termination right proposed by Apollo relating to a decline in Aspen’s book value would be replaced with a termination right relating to net losses incurred by Aspen from catastrophic events occurring prior to the closing date.

On August 19, 2018, representatives of Aspen’s financial advisors, at the direction of the Strategy Committee, discussed with representatives of Apollo the key terms of Aspen’s counterproposal to Apollo, and

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following such discussion sent Apollo a term sheet that summarized such key terms. Later on August 19, 2018, the Strategy Committee held a meeting, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, to discuss Apollo’s potential response to this counterproposal.

On August 20, 2018, Apollo communicated to representatives of Aspen’s financial advisors a further revised offer to acquire 100% of Aspen’s outstanding ordinary shares for $42.75 per ordinary share in cash and responded to the terms of Aspen’s counterproposal relating to the proposed termination right, closing conditions and related provisions as reflected in a revised term sheet.

On August 20 and 21, 2018, the Strategy Committee held meetings, at which members of senior management and representatives of Aspen’s financial advisors and outside legal counsel were present, to discuss Apollo’s further revised offer and Aspen’s potential response regarding the proposed termination right, closing conditions and related provisions. After the meeting on August 21, 2018, representatives of Aspen’s financial advisors, at the direction of the Strategy Committee, sent representatives of Apollo a revised draft of the term sheet reflecting Aspen’s counterproposal regarding such terms.

On August 21, 2018, representatives of Aspen’s financial advisors and outside legal counsel discussed with Apollo and its legal advisors the specific terms of the proposed termination right, closing conditions and related provisions. Later on August 21, 2018, representatives of Apollo sent Aspen’s financial advisors a revised draft of the term sheet reflecting Apollo’s further revised counterproposal.

At a telephonic Board meeting on August 21, 2018, at which members of Aspen’s senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present, the Board discussed the developments in the discussions between Aspen and Apollo since the Board meeting on August 17, 2018, and the terms of the proposed termination right, closing conditions and related provisions being negotiated by the parties. At the end of the meeting, the Board directed Aspen’s senior management team, financial advisors and outside legal counsel to negotiate the terms of the definitive merger agreement with Apollo.

During the period from August 22, 2018 to August 27, 2018, representatives of Willkie, with the assistance of Goldman Sachs and J.P. Morgan and under the direction of the Strategy Committee and Aspen’s senior management, negotiated the terms and conditions of the merger agreement, equity commitment letter and limited guarantee with Apollo’s legal advisors.

The Board, other than Mr. Pearlman, who was unable to attend, met by telephone on August 27, 2018. Members of Aspen’s senior management and representatives of Aspen’s financial advisors and outside legal counsel were also present. At that meeting, representatives of Aspen’s financial advisors reviewed with the Board the process to identify a potential buyer of Aspen and their respective financial analyses of the merger consideration, as more fully described below under the heading “ — Opinion of Aspen’s Financial Advisors”. Thereafter, representatives of Aspen’s financial advisors each rendered their respective oral opinions to the Board, which opinions were subsequently confirmed in their respective written opinions dated August 27, 2018, that, as of the date of such opinions and based upon and subject to the factors and assumptions set forth therein, the $42.75 in cash per ordinary share to be paid to the holders of ordinary shares pursuant to the merger agreement was fair from a financial point of view to such holders. Representatives of Willkie then reviewed the terms and conditions of the proposed merger agreement with Apollo, including the provisions of the merger agreement relating to the bye-law amendment. After discussion, and in light of the Board’s review and, among other things, consideration of the factors described under “—Aspen’s Reasons for the Merger and Recommendation of the Board,” the Board approved the merger, the merger agreement, the statutory merger agreement, and the bye-law amendment and resolved that the merger proposal and the bye-law amendment be submitted to Aspen’s shareholders for their consideration at the special general meeting. In approving the merger, the merger agreement, and the statutory merger agreement, the Board determined that the fair value for (i) each ordinary share to be no greater than $42.75, without interest and less any applicable withholding taxes, (ii) each issued and outstanding 5.95% preference share, to be the continuation of each such 5.95% preference

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share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged and (iii) each issued and outstanding 5.625% preference share, to be the continuation of each such 5.625% preference share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged.

Following the Board meeting on August 27, 2018, Aspen and Parent, an affiliate of the Apollo Funds, entered into the merger agreement. Apollo and Aspen issued a joint press release announcing the transaction prior to the opening of trading markets in Europe on August 28, 2018.

Reasons for the Merger; Recommendation of the Board of Directors; Fairness of the Merger

The Board has unanimously, by all directors present at a duly called meeting, adopted resolutions whereby it has (1) determined that the bye-law amendment is advisable and in the best interests of Aspen, and authorized and approved the bye-law amendment, (2) determined that the merger consideration constitutes no less than fair value for each ordinary share in accordance with the Companies Act, that the preference shares of the surviving company constitutes fair value for each of the preference shares of Aspen in accordance with the Companies Act and that the merger, on the terms and subject to the conditions set forth in the merger agreement and the statutory merger agreement, is fair to, and in the best interests of, Aspen and its shareholders, (3) approved the merger, the merger agreement and the statutory merger agreement, and (4) resolved to recommend approval of the bye-law amendment, the merger, the merger agreement, and the statutory merger agreement to Aspen’s shareholders for their consideration at the special general meeting. Accordingly, the Board recommends that Aspen’s shareholders vote “FOR” the merger proposal.

For purposes of Section 106(2)(b)(i) of the Companies Act, the Board has unanimously, by all directors present at a duly called meeting, determined that the fair value for (i) each ordinary share to be no greater than $42.75, without interest and less any applicable withholding taxes, (ii) each 5.95% preference share to be the continuation of each such preference share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged and (iii) each 5.625% preference share to be the continuation of each such preference share as a preference share of Aspen as the surviving company following the merger with all of its relative rights, terms and conditions remaining unchanged.

Positive Factors Relating to the Merger

As described in the section of this proxy statement titled “The Merger — Background of the Merger,” the Board, prior to and in reaching its unanimous determination by all directors present at its meeting on August 27, 2018 to approve the bye-law amendment and that the merger, on the terms and subject to the conditions set forth in the merger agreement and the statutory merger agreement, is fair to, and in the best interests of, Aspen, consulted with Aspen’s management, financial advisors, and outside legal counsel and considered a variety of potentially positive factors relating to the merger, including, but not limited to, the following:

Treatment of Ordinary Shares

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Treatment of Preference Shares

Terms of the Merger Agreement

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Risk and Other Considerations of the Merger

In the course of its deliberations, the Board, in consultation with Aspen management, financial advisors, and outside legal counsel, also considered a variety of risks and other potentially negative factors relating to the merger, including the following:

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The foregoing discussion of the factors considered by the Board is not intended to be exhaustive, but rather a summary of the material factors considered by the Board. In reaching its decision to approve the merger agreement, including the merger and other transactions contemplated by the merger agreement, the Board did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The Board considered the various factors as a whole, including discussions with, and questioning of, Aspen’s management, financial advisors, and outside legal counsel, and overall considered the factors to be favorable to, and to support, its determination.

The foregoing discussion of the information and factors considered by the Board is forward-looking in nature. This information should be read in light of the factors described under the section of this proxy statement titled “Cautionary Statement Concerning Forward-Looking Information.”

The Board recommends unanimously, by all directors present at a duly called meeting, that you vote “FOR” the approval of the Merger Agreement.

Opinion of Aspen’s Financial Advisor (Goldman Sachs)

Goldman Sachs rendered its oral opinion to the Board, which opinion was subsequently confirmed in a written opinion dated August 27, 2018, that, as of the date of such opinion and based upon and subject to the factors and assumptions set forth therein, the $42.75 in cash per ordinary share to be paid to the holders (other than Parent and its affiliates) of ordinary shares pursuant to the merger agreement was fair from a financial point of view to such holders.

The full text of the written opinion of Goldman Sachs, dated August 27, 2018, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex B to this proxy statement. Goldman Sachs provided advisory services and its opinion for the information and assistance of the Board in connection with the consideration of the merger. The Goldman Sachs opinion is not a recommendation as to how any holder of Aspen’s ordinary shares should vote with respect to the merger, or any other matter.

In connection with rendering its opinion described above and performing the related financial analysis, Goldman Sachs reviewed, among other things:

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Goldman Sachs also held discussions with members of the senior management of Aspen regarding their assessment of the past and current business operations, financial condition and future prospects of Aspen; reviewed the reported price and trading activity for the ordinary shares of Aspen; compared certain financial and stock market information for Aspen with similar information for certain other companies the securities of which are publicly traded; reviewed the financial terms of certain recent business combinations in the property and casualty insurance and reinsurance industries and in other industries; and performed such other studies and analyses, and considered such other factors, as Goldman Sachs deemed appropriate.

For purposes of rendering its opinion, Goldman Sachs, with Aspen’s consent, relied upon and assumed the accuracy and completeness of all of the financial, legal, regulatory, tax, accounting and other information provided to, discussed with or reviewed by Goldman Sachs, without assuming any responsibility for independent verification thereof. In that regard, Goldman Sachs assumed, with Aspen’s consent, that the Forecasts were reasonably prepared on a basis reflecting the best currently available estimates and judgments of the management of Aspen. Goldman Sachs did not make an independent evaluation or appraisal of the assets and liabilities (including any contingent, derivative or other off-balance-sheet assets and liabilities) of Aspen or any of its subsidiaries, nor was any such evaluation or appraisal furnished to Goldman Sachs. Goldman Sachs is not an actuary and its services did not include any actuarial determination or evaluation by Goldman Sachs. Goldman Sachs did not make any attempt to evaluate actuarial assumptions and relied on Aspen’s actuaries with respect to reserve adequacy. In that regard, Goldman Sachs did not make any analysis of, and did not express any opinion as to, the adequacy of loss and loss adjustments expenses reserves. Goldman Sachs assumed that all governmental, regulatory or other consents and approvals necessary for the consummation of the merger will be obtained without any adverse effect on the expected benefits of the merger in any way meaningful to Goldman Sachs’ analysis. Goldman Sachs assumed that the merger will be consummated on the terms set forth in the merger agreement, without the waiver or modification of any term or condition the effect of which would be in any way meaningful to Goldman Sachs’ analysis.

Goldman Sachs’ opinion does not address the underlying business decision of Aspen to engage in the merger, or the relative merits of the merger as compared to any strategic alternatives that may be available to Aspen, nor does it address any legal, regulatory, tax or accounting matters. Goldman Sachs’ opinion addresses only the fairness from a financial point of view to the holders (other than Parent and its affiliates) of ordinary shares of Aspen, as of the date of the opinion, of the of the $42.75 in cash per ordinary share to be paid to such holders pursuant to the merger agreement. Goldman Sachs did not express any view on, and its opinion does not address, any other term or aspect of the merger agreement or the merger or any term or aspect of any other agreement or instrument contemplated by the merger agreement or entered into or amended in connection with the merger, including the fairness of the merger to, or any consideration received in connection therewith by, the holders of any other class of securities, creditors, or other constituencies of Aspen, nor as to the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of Aspen, or class of such persons, in connection with the merger, whether relative to the $42.75 in cash per ordinary share to be paid to the holders (other than Parent and its affiliates) of ordinary shares of Aspen pursuant to the merger agreement or otherwise. Goldman Sachs did not express any opinion as to the impact of the merger on the solvency or viability of Aspen, Merger Sub or Parent or the ability of Aspen, Merger Sub or Parent to pay their respective obligations when they come due. Goldman Sachs’ opinion was necessarily based on economic, monetary, market and other conditions as in effect on, and the information made available to Goldman Sachs as of, the date of its opinion and Goldman Sachs assumed no responsibility for updating, revising or reaffirming its

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opinion based on circumstances, developments or events occurring after such date. Goldman Sachs’ advisory services and the opinion expressed in its opinion were provided for the information and assistance of the Board in connection with its consideration of the merger and such opinion does not constitute a recommendation as to how any holder of ordinary shares should vote with respect to such merger or any other matter. The opinion was approved by a fairness committee of Goldman Sachs.

Goldman Sachs and its affiliates are engaged in advisory, underwriting and financing, principal investing, sales and trading, research, investment management and other financial and non-financial activities and services for various persons and entities. Goldman Sachs and its affiliates and employees, and funds or other entities they manage or in which they invest or have other economic interests or with which they co-invest, may at any time purchase, sell, hold or vote long or short positions and investments in securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments of Aspen, Parent, any of their respective affiliates and third parties, including Apollo and its affiliates and portfolio companies, or any currency or commodity that may be involved in the transaction contemplated by the merger agreement for the accounts of Goldman Sachs and its affiliates and employees and their customers. Goldman Sachs acted as financial advisor to Aspen in connection with, and participated in certain of the negotiations leading to, the transaction contemplated by the merger agreement. Goldman Sachs has provided certain financial advisory and/or underwriting services to Aspen and/or its affiliates from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation, including having acted as co-manager with respect to a public offering of Aspen’s 5.95% Fixed-to-Floating Rate Perpetual Non-Cumulative Preference Shares (aggregate principal amount $250,000,000) in September 2016. During the two year period ended August 27, 2018, Goldman Sachs has recognized compensation for financial advisory and/or underwriting services provided by its Investment Banking Division to Aspen and/or its affiliates of approximately $20,000. Goldman Sachs also has provided certain financial advisory and/or underwriting services to Apollo and/or its affiliates and portfolio companies from time to time for which the Investment Banking Division of Goldman Sachs has received, and may receive, compensation, including having acted as financial advisor to Gala Coral Group Limited, a portfolio company of Apollo, in connection with its merger with Ladbrokes plc in November 2016; as lead arranger with respect to a public offering by Laureate Education Inc., a portfolio company of Apollo, of its 8.250% Senior Notes due 2025 (aggregate principal amount $800,000,000) in April 2017; as joint agent with respect to a term loan facility (aggregate principal amount $2,900,000,000) of West Corporation, a portfolio company of Apollo, in October 2017; as financial advisor to EaglePicher Industries Inc., a subsidiary of Vectra Corporation, a portfolio company of Apollo, in connection with its sale in December 2017; as administrative agent, joint lead arranger and joint bookrunner in connection with a term loan facility (aggregate principal amount $2,200,000,000) and revolving credit facility (aggregate principal amount $400,000,000) of VICI Properties Inc., a portfolio company of Apollo, in December 2017; as joint lead arranger and joint bookrunner with respect to a revolving credit facility (aggregate principal amount $3,500,000,000) of Vistra Energy Corp., a portfolio company of Apollo, in December 2017; as joint lead arranger and joint bookrunner with respect to a term loan (aggregate principal amount $4,700,000,000) and revolving credit facility (aggregate principal amount $1,000,000,000) of Caesars Entertainment Corporation, a portfolio company of Apollo, in December 2017; as bookrunner with respect to an initial public offering of 105,000,000 shares of common stock of The ADT Corporation, a portfolio company of Apollo, in January 2018; and as financial advisor to Athora Holding Ltd., a portfolio company of Apollo, in connection with its acquisition of Generali Belgium SA in April 2018. During the two year period ended August 27, 2018, Goldman Sachs has recognized compensation for financial advisory and/or underwriting services provided by its Investment Banking Division to Parent and/or its affiliates, including Apollo, of approximately $117,600,000. Goldman Sachs may also in the future provide financial advisory and/or underwriting services to Aspen, Parent, Apollo and their respective affiliates and portfolio companies, as applicable, for which the Investment Banking Division of Goldman Sachs may receive compensation. Affiliates of Goldman Sachs also may have co-invested with Apollo and its affiliates from time to time and may have invested in limited partnership units of affiliates of Apollo from time to time and may do so in the future.

The Board selected Goldman Sachs as its financial advisor because it is an internationally recognized investment banking firm that has substantial experience in transactions similar to the merger. Pursuant to a letter

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agreement, dated August 1, 2012, as amended and restated, Aspen engaged Goldman Sachs to act as its financial advisor in connection with a sale of all or a portion of Aspen and certain other matters. The engagement letter between Aspen and Goldman Sachs provides for a fee payable in connection with the contemplated transaction that is estimated, based on the information available as of the date of announcement, at approximately $22,000,000, all of which is contingent upon consummation of the transaction. In addition, Aspen has agreed to reimburse Goldman Sachs for certain of its expenses, including attorneys’ fees and disbursements, and to indemnify Goldman Sachs and related persons against various liabilities, including certain liabilities under the federal securities laws.

Opinion of Aspen’s Financial Advisor (J.P. Morgan)

Pursuant to an engagement letter, dated March 16, 2018, Aspen retained J.P. Morgan as its financial advisor in connection with the proposed merger.

At the meeting of the Board on August 27, 2018, J.P. Morgan rendered its oral opinion to the Board, which opinion was subsequently confirmed in a written opinion dated August 27, 2018, that, as of the date of such opinion and based upon and subject to the factors and assumptions set forth therein, the $42.75 in cash per ordinary share to be paid to the holders of ordinary shares pursuant to the merger agreement was fair from a financial point of view to such holders.

The full text of the written opinion of J.P. Morgan, dated August 27, 2018, which sets forth the assumptions made, matters considered and limits on the review undertaken, is attached as Annex C to this proxy statement and is incorporated herein by reference. Aspen’s shareholders are urged to read the opinion in its entirety. J.P. Morgan’s written opinion is addressed to the Board, is directed only to the consideration to be paid in the merger and does not constitute a recommendation to any shareholder of Aspen as to how such shareholder should vote at the special general meeting. The summary of the opinion of J.P. Morgan set forth in this proxy statement is qualified in its entirety by reference to the full text of such opinion.

In arriving at its opinion, J.P. Morgan, among other things:

In addition, J.P. Morgan held discussions with certain members of the management of Aspen with respect to certain aspects of the merger, the past and current business operations of Aspen, the financial condition and future prospects and operations of Aspen, and certain other matters J.P. Morgan believed necessary or appropriate to its inquiry.

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In giving its opinion, J.P. Morgan relied upon and assumed the accuracy and completeness of all information that was publicly available or was furnished to or discussed with J.P. Morgan by Aspen or otherwise reviewed by or for J.P. Morgan. J.P. Morgan did not independently verify any such information or its accuracy or completeness, and, pursuant to its engagement letter with Aspen, did not assume any obligation to undertake any such independent verification. J.P. Morgan did not conduct or was not provided with any valuation or appraisal of any assets or liabilities, or conduct any actuarial analysis, nor did J.P. Morgan evaluate the solvency of Aspen, Merger Sub or Parent under any state or federal laws relating to bankruptcy, insolvency or similar matters. In relying on financial analyses and forecasts provided to J.P. Morgan or derived therefrom, J.P. Morgan assumed that they were reasonably prepared based on assumptions reflecting the best currently available estimates and judgments by management as to the expected future results of operations and financial condition of Aspen to which such analyses or forecasts relate. J.P. Morgan expressed no view as to such analyses or forecasts or the assumptions on which they were based. J.P. Morgan also assumed that the merger and the other transactions contemplated by the merger agreement will be consummated as described in the merger agreement. J.P. Morgan also assumed that the representations and warranties made by Aspen, Merger Sub and Parent in the merger agreement and the related agreements are and will be true and correct in all respects material to its analysis. J.P. Morgan is not a legal, regulatory, actuarial or tax expert and relied on the assessments made by advisors to Aspen with respect to such issues. J.P. Morgan further assumed that all material governmental, regulatory or other consents and approvals necessary for the consummation of the merger will be obtained without any adverse effect on Aspen or on the contemplated benefits of the merger.

J.P. Morgan’s opinion was necessarily based on economic, market and other conditions as in effect on, and the information made available to J.P. Morgan as of, the date of such opinion. J.P. Morgan’s opinion noted that subsequent developments may affect J.P. Morgan’s opinion, and that J.P. Morgan does not have any obligation to update, revise, or reaffirm such opinion. J.P. Morgan’s opinion is limited to the fairness, from a financial point of view, of the consideration to be paid to the holders of ordinary shares in the proposed merger and J.P. Morgan has expressed no opinion as to the fairness of any consideration paid in connection with the merger to the holders of any other class of securities, creditors or other constituencies of Aspen or as to the underlying decision by Aspen to engage in the merger. Furthermore, J.P. Morgan expressed no opinion with respect to the amount or nature of any compensation to any officers, directors, or employees of any party to the merger, or any class of such persons relative to the consideration to be paid to the holders of ordinary shares in the merger or with respect to the fairness of any such compensation.

As a part of its investment banking business, J.P. Morgan and its affiliates are continually engaged in the valuation of businesses and their securities in connection with mergers and acquisitions, investments for passive and control purposes, negotiated underwritings, secondary distributions of listed and unlisted securities, private placements, and valuations for estate, corporate and other purposes. J.P. Morgan was selected to advise Aspen with respect to the merger on the basis of such experience and its familiarity with Aspen.

For services rendered in connection with the merger, Aspen has agreed to pay J.P. Morgan a fee of approximately $12,000,000, $2,500,000 of which was payable following delivery of J.P. Morgan’s opinion and the remainder of which is contingent and payable upon consummation of the merger. J.P. Morgan may also receive a fee from Aspen in the event Aspen receives a break-up fee in connection with the termination or abandonment of the merger, or the failure of the merger to occur. In addition, Aspen has agreed to reimburse J.P. Morgan for its reasonable expenses incurred in connection with its services, including the reasonable fees and disbursements of counsel, and will indemnify J.P. Morgan against certain liabilities arising out of J.P. Morgan’s engagement. During the two years preceding the date of its opinion, neither J.P. Morgan nor its affiliates had any material commercial or investment banking relationships with Aspen. During the two years preceding the date of its opinion, J.P. Morgan and its affiliates have had commercial or investment banking relationships with Apollo, for which J.P. Morgan and such affiliates have received customary compensation. J.P. Morgan and its affiliates have provided services during such period including acting as joint lead manager on Apollo’s par preferred transaction which closed in March 2017, joint lead manager on Apollo’s senior notes offering which closed in March 2018 and joint lead manager on Apollo’s perpetual preferred transaction which closed in March 2018.

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During such period, J.P. Morgan and its affiliates have provided financial advisory, bank financing and debt and equity underwriting services to portfolio companies of Apollo and its affiliates that are unrelated to the merger, for which J.P. Morgan and such affiliates have received customary compensation. In addition, during such period, J.P. Morgan and its affiliates have provided treasury services to Apollo, for customary compensation. During the two year period preceding the delivery of its opinion, the aggregate fees received by J.P. Morgan from Apollo and certain of its affiliates were approximately $88.1 million. In the ordinary course of J.P. Morgan’s businesses, J.P. Morgan and its affiliates may actively trade the debt and equity securities of Aspen, Apollo or its affiliates or portfolio companies for the account of J.P. Morgan or for the accounts of its customers and, accordingly, J.P. Morgan may at any time hold long or short positions in such securities. In addition, J.P. Morgan and its affiliates hold, in each case on a proprietary basis, less than 1% of the outstanding ordinary shares of Aspen and 2.99% of the outstanding membership interests of Apollo.

Summary of Material Financial Analyses of Aspen’s Financial Advisors

The following is a summary of the material financial analyses performed by Aspen’s financial advisors in connection with rendering their opinions described above. The following summary, however, does not purport to be a complete description of the financial analyses performed by Aspen’s financial advisors. The order of analyses described does not represent the relative importance or weight given to those analyses by Aspen’s financial advisors. Each of the summaries of financial analyses indicates the financial advisor that performed such analysis. A financial analysis performed by one of the financial advisors was not relied upon by and is not attributable to the other financial advisor. Some of the summaries of the financial analyses include information presented in tabular format. The tables must be read together with the full text of each summary and are alone not a complete description of the financial analyses performed by Aspen’s financial advisors. Considering the data set forth below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of the analyses of Aspen’s financial advisors. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before August 24, 2018, the last trading day prior to the date on which the Board adopted a resolution approving the merger agreement, and is not necessarily indicative of current market conditions.

Analysis at Various Prices. Aspen’s financial advisors analyzed the merger consideration of $42.75 per ordinary share of Aspen in relation to the closing price of Aspen’s ordinary shares on August 24, 2018; the closing price of Aspen’s ordinary shares on March 2, 2018, the last trading date prior to the announcement that AXA S.A. had entered into an agreement to acquire XL Group Ltd.; the closing price of Aspen’s ordinary shares on March 8, 2018, the last trading date prior to the publication of the article in Insurance Insider reporting that Aspen had retained Goldman Sachs and J.P. Morgan to advise on strategic alternatives; the one-month, three-month and one-year volume-weighted average trading prices of Aspen’s ordinary shares and the one-year low and one-year high prices of Aspen’s ordinary shares. The following table presents the results of this analysis:

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Aspen’s financial advisors also calculated various financial multiples and ratios for Aspen using (i) the closing price of Aspen’s ordinary shares on August 24, 2018 and (ii) the merger consideration of $42.75 per ordinary share of Aspen.

The multiples and ratios were based on information from the Forecasts, FactSet Research Systems, Inc., SNL Financial, Bloomberg L.P., public filings and other publicly available sources. Aspen’s financial advisors calculated, among other things:

Aspen’s financial advisors presented analysis at various prices for reference purposes only and not as a component of Aspen’s financial advisors’ respective fairness analyses.

Selected Public Trading Multiples. Using publicly available information, Aspen’s financial advisors compared selected financial data of Aspen with similar data for selected publicly traded companies engaged in businesses that Aspen’s financial advisors judged to be analogous to Aspen. The companies selected by Aspen’s financial advisors were as follows:

None of the selected companies reviewed is identical to Aspen. Certain of these companies may have characteristics that are materially different from those of Aspen. However, the companies were selected, among other reasons, because they are publicly traded companies with operations and businesses that, for purposes of Aspen’s financial advisors’ analyses, may be considered similar to those of Aspen. The analyses necessarily involve complex considerations and judgments concerning differences in financial and operational characteristics of the companies involved and other factors that could affect the companies differently than they would affect Aspen.

Using publicly available information, Aspen’s financial advisors calculated, for each selected company: (a) the ratio of such company’s share price to the equity research analyst estimate for such company’s 2018 EPS;

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(b) the ratio of such company’s share price to the equity research analyst estimate for such company’s 2019 EPS; (c) the ratio of such company’s share price to its BV, including accumulated other comprehensive income, calculated as of June 30, 2018; and (d) the ratio of such company’s share price to its TBV, including accumulated other comprehensive income, calculated as of June 30, 2018.

The following table represents the results of this analysis:

J.P. Morgan also considered the ratio of Aspen’s ordinary share price to its BV of 1.00x, including accumulated other comprehensive income, using BV as of June 30, 2018 and the most recently reported ordinary share price, and the ratio of Aspen’s ordinary share price to its TBV of 1.02x, including accumulated other comprehensive income, using TBV as of June 30, 2018 and the most recently reported ordinary share price. Based on the results of this analysis and other factors which J.P. Morgan considered appropriate based on its experience and judgment, J.P. Morgan selected multiple reference ranges for Aspen as follows:

After applying these ranges to Aspen’s estimated 2018 EPS of $2.79 and estimated 2019 EPS of $3.44, each of which were based on the Forecasts; Aspen’s diluted BV of $38.21 per ordinary share as of June 30, 2018; and Aspen’s diluted TBV of $37.77 per ordinary share as of June 30, 2018, J.P. Morgan’s analysis indicated the following implied equity value per share ranges for the ordinary shares, rounded to the nearest $0.01:

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Selected Transactions Analysis. Using publicly available information, Aspen’s financial advisors reviewed selected transactions involving acquired businesses that, for purposes of Aspen’s financial advisors’ analyses and based on their experience and judgment, were considered to be analogous to Aspen’s business. Specifically, Aspen’s financial advisors reviewed the following transactions involving companies in the Bermuda (re)insurance business:

Certain of these transactions may have characteristics that are materially different from those of the merger and while none of the companies that participated in the selected transactions or the selected transactions are directly comparable to Aspen or the merger, respectively, the companies that participated in the selected transactions are companies with operations that, for the purpose of analysis, may be considered similar to certain to Aspen’s results, market size and product profile.

Using publicly available information, Aspen’s financial advisors calculated, for each selected transaction: (a) the ratio of the deal value to the applicable target company’s BV, including accumulated other comprehensive income; (b) the ratio of the deal value to the applicable target company’s TBV, including accumulated other comprehensive income; and (c) the ratio of the deal value to the applicable target company’s expected EPS for the twelve-month period immediately following the applicable selected transaction (NTM). Based on the results of this analysis, Aspen’s financial advisors selected multiple reference ranges for Aspen as follows:

After applying these ranges to Aspen’s diluted BV of $38.21 per ordinary share as of June 30, 2018; Aspen’s diluted TBV of $37.77 per ordinary share; and Aspen’s estimated EPS for the twelve-month period beginning July 1, 2018 of $3.01, as provided by Aspen’s management, this analysis indicated the following implied equity value per share ranges for the ordinary shares, rounded to the nearest $0.01:

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Illustrative Present Value of Future Share Price Analysis. Goldman Sachs performed an illustrative analysis of the implied present value of an illustrative future value per share of Aspen’s ordinary shares, which is designed to provide an indication of the present value of a theoretical future value of a company’s equity as a function of such company’s financial multiples. For this analysis, Goldman Sachs first calculated the implied equity values per ordinary share of Aspen as of the fiscal years ended December 31, 2018 and 2019, respectively, by applying an illustrative range of forward EPS multiples of 9.0x to 12.0x to EPS estimates for each of the fiscal years ended December 31, 2019 and 2020, respectively, contained in the Forecasts. These illustrative multiple estimates were derived by Goldman Sachs utilizing its professional judgment and experience, taking into account, among other things, historical average price to earnings multiples for Aspen and the selected companies referenced in the analysis above. Goldman Sachs then discounted the implied future value per ordinary share of Aspen back to June 30, 2018, using an illustrative discount rate of 7.27%, reflecting an estimate of Aspen’s cost of equity. Goldman Sachs derived such illustrative estimated cost of equity by application of the Capital Asset Pricing Model, which requires certain company specific inputs, including a beta for the company, as well as certain financial metrics for the United States financial markets generally (“CAPM”).

Goldman Sachs also performed an illustrative analysis of the implied present value of an illustrative future value per share of Aspen’s ordinary shares as a function of its price to future BV. For this analysis, Goldman Sachs first calculated the implied equity values per ordinary share as of December 31, 2018, 2019 and 2020, respectively, by applying an illustrative range of BV of shareholders’ equity multiples of 0.90x to 1.20x to BV per share estimates as of December 31, 2019, 2020 and 2021, respectively, contained in the Forecasts. These illustrative multiple estimates were derived by Goldman Sachs utilizing its professional judgment and experience, taking into account, among other things, historical average of price to BV multiples for Aspen and the selected companies referenced in the analysis above. Goldman Sachs then discounted the implied future value per share of Aspen back to June 30, 2018, using an illustrative discount rate of 7.27%, reflecting an estimate of Aspen’s cost of equity. Goldman Sachs derived such illustrative estimated cost of equity by application of CAPM.

The foregoing analysis resulted in a range of implied present values per share of Aspen’s ordinary shares of $30.37 to $44.12.

Premia Paid Analysis. Goldman Sachs analyzed Thomson Reuters data regarding the median premium paid in all cash acquisitions of publicly traded companies in North America each year during the period January 2013 through August 24, 2018 in which the target company had an implied equity value of over $500,000,000 based on the consideration paid in the applicable transaction. For the entire period, Goldman Sachs reviewed the median premium reflected by the respective prices paid in the transactions to the respective closing prices of the target companies’ shares one day prior to the announcement of the transactions. The following shows a summary of the results of the review:

Based on its review of the foregoing data and its professional judgment and experience, Goldman Sachs applied a reference range of illustrative premia of 20.1% to 35.2% to the undisturbed price of $35.95 per ordinary share of Aspen as of March 2, 2018, the last trading date prior to the announcement that AXA S.A. had entered into an agreement to acquire XL Group Ltd. The analysis resulted in a range of implied values from $43.18 to $48.60 per ordinary share.

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Dividend Discount Analysis.

Goldman Sachs’ Dividend Discount Analysis

Using the Forecasts, Goldman Sachs performed a dividend discount analysis on Aspen to determine a range of equity values for the Company’s fully diluted ordinary shares. Goldman Sachs discounted the estimated dividend streams from Aspen for the period 2018 through 2020 as reflected in the Forecasts and the range of terminal values to derive present values, as of June 30, 2018, of Aspen. Goldman Sachs calculated a range of terminal values for Aspen by applying price to BV multiples ranging from 0.90x to 1.20x to the projected BV of Aspen in 2020 as reflected in the Forecasts. These illustrative BV multiple estimates were derived by Goldman Sachs utilizing its professional judgment and experience, taking into account, among other things, historical average of price to BV multiples for Aspen. Goldman Sachs used a range of discount rates from 6.73% to 7.81%, reflecting estimates of Aspen’s cost of equity. Goldman Sachs derived such illustrative estimated cost of equity by application of CAPM.

This analysis implied an equity value per share of $32.56 to $43.76 per ordinary share of Aspen as of June 30, 2018 based on fully diluted shares outstanding provided by Aspen’s management.

J.P. Morgan’s Dividend Discount Analysis

J.P. Morgan conducted a dividend discount analysis to determine a range of equity values for the Company’s fully diluted ordinary shares, assuming the Company continued to operate as a standalone entity. The range was determined by adding the present value of an estimated future dividend stream for Aspen over a three-year period from 2018 through 2020, using the Forecasts and the present value of an estimated terminal value of the ordinary shares at the end of 2020. For purposes of calculating the terminal value, J.P. Morgan was directed by Aspen’s management to use a terminal growth rate of 1.00%-2.00% and a payout ratio of 70% (among other terminal year assumptions). In performing its analysis, J.P. Morgan assumed a cost of equity range of 7.00-8.00%, which range was chosen by J.P. Morgan taking into account macroeconomic assumptions, estimates of risk, Aspen’s capital structure and other appropriate factors.

This analysis implied an equity value per share of $37.17 to $52.39 per ordinary share of Aspen as of June 30, 2018 based on fully diluted shares outstanding provided by Aspen’s management.

The foregoing summary of certain material financial analyses does not purport to be a complete description of the analyses or data presented by Aspen’s financial advisors. The preparation of a fairness opinion is a complex process and is not necessarily susceptible to partial analysis or summary description. Selecting portions of the analyses or of the summary set forth above, without considering the analyses as a whole, could create an incomplete view of the processes underlying Aspen’s financial advisors’ opinions. In arriving at its respective fairness determination, each of Aspen’s financial advisors considered the results of all of its analyses and did not attribute any particular weight to any factor or analysis considered by it. Rather, each of Aspen’s financial advisors made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of its analyses. Other than Aspen or Parent, no company or transaction used in the above analyses as a comparison is directly comparable to Aspen or Parent or the contemplated transaction.

Aspen’s financial advisors prepared these analyses for purposes of providing their respective opinions to the Board as to the fairness from a financial point of view of the total consideration to be paid to the holders of ordinary shares of Aspen in the proposed merger. These analyses do not purport to be appraisals or necessarily reflect the prices at which businesses or securities actually may be sold. Analyses based upon forecasts of future results are not necessarily indicative of actual future results, which may be significantly more or less favorable than suggested by these analyses. Because these analyses are inherently subject to uncertainty, being based upon numerous factors or events beyond the control of the parties or their respective advisors, none of Aspen, Parent, Goldman Sachs, J.P. Morgan or any other person assumes responsibility if future results are materially different from those forecasted.

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The consideration was determined through arm’s-length negotiations between Aspen and Parent and was approved by the Board. Aspen’s financial advisors provided advice to Aspen during these negotiations Aspen’s financial advisors did not, however, recommend any specific amount of consideration to Aspen or the Board or that any specific amount of consideration constituted the only appropriate consideration for the merger. As described above, J.P. Morgan’s and Goldman Sachs’ opinions to the Board were one of many factors taken into consideration by the Board in making its determination to approve the merger agreement. The foregoing summary does not purport to be a complete description of the analyses performed by each of J.P. Morgan and Goldman Sachs in connection with the fairness opinions and is qualified in its entirety by reference to the written opinions of Goldman Sachs and J.P. Morgan included as Annexes B and C to this proxy statement, respectively.

Certain Aspen Prospective Financial Information

Aspen management does not as a matter of course make public projections as to future performance or earnings, particularly given the significant unpredictability inherent in its business. However, Aspen provided, among other information, certain financial projections prepared by Aspen’s management to the Board, to Goldman Sachs and J.P. Morgan, financial advisors to Aspen, and to each of the potential bidders for Aspen in connection with their respective evaluations of the merger (the “financial projections”). The financial projections were not developed for the purposes of providing earnings guidance.

The financial projections represent only one scenario in a wide range of potential outcomes. While presented with numeric specificity, the financial projections reflect numerous estimates and assumptions with respect to industry performance, general business, economic, regulatory, market, and financial conditions, and other future events, as well as matters specific to Aspen’s business, all of which are inherently uncertain and difficult to predict and many of which are beyond Aspen’s control. These financial projections are subjective in many respects. The financial projections cover multiple years and such information by its nature becomes less reliable with each successive year. The financial projections may also be affected by Aspen’s ability to achieve strategic goals, objectives, and targets over the applicable periods. As such, the financial projections constitute forward-looking information and are subject to risks and uncertainties, including the various risks set forth in the sections of this proxy statement titled “Cautionary Statement Concerning Forward-Looking Information” and in Aspen’s most recent reports on Form 10-K and Form 10-Q and other documents filed with or furnished to the SEC. Aspen’s shareholders should read the section of this proxy statement titled “Cautionary Statement Concerning Forward-Looking Information” and such reports filed with the SEC for additional information regarding the risks inherent in forward-looking information such as the financial projections.

The financial projections were not prepared with a view toward public disclosure, the published guidelines of the SEC regarding projections, or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information. In view of Aspen’s management, the financial projections were prepared on a reasonable basis. However, the financial projections are not factual, and should not be relied upon as being necessarily indicative of future results, and readers of this proxy statement are cautioned not to place undue reliance on the financial projections. Neither Aspen’s independent registered public accounting firm, nor any other independent accountants, have compiled, examined or performed any procedures with respect to the financial projections included below, nor have they expressed any opinion or any other form of assurance on such information or its achievability, and they assume no responsibility for, and disclaim any association with, the financial projections. Furthermore, the financial projections do not take into account any circumstances or events occurring after the date they were prepared.

Certain of the financial projections set forth herein may be considered non-generally accepted accounting principles ( “non-GAAP”) financial measures. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information presented in compliance with generally accepted accounting principles ( “GAAP”). Non-GAAP financial measures as used in the financial projections may also not be comparable to similarly titled amounts used by other companies or persons.

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The financial projections set forth below do not give effect to the merger and do not take into account the effect of any potential failure for the merger to be consummated.

You are strongly cautioned not to place undue reliance on the financial projections set forth below. The inclusion of the financial projections in this proxy statement should not be regarded as an indication that any of Aspen, Parent or their affiliates, advisors or representatives considered or consider the financial projections to be predictive of actual future events, and the financial projections should not be relied upon as such. None of Aspen, Parent or their respective affiliates, advisors, officers, directors or representatives can give any assurance that actual results will not materially differ from the financial projections, and none of them undertakes any obligation to update or otherwise revise or reconcile the financial projections to reflect circumstances existing after the date such financial projections were generated or to reflect the occurrence of future events even in the event that any or all of the assumptions underlying the financial projections are shown to be in error. None of Aspen, Parent or their respective affiliates, advisors or representatives makes any representation to any other person regarding the financial projections. The financial projections are not being included in this proxy statement to influence a shareholder’s decision regarding how to vote on any given proposal, but because the financial projections were provided to Goldman Sachs and J.P. Morgan. These financial projections are for illustrative purposes and should not be considered an indication of what Aspen may do in the future.

The CIM distributed by Aspen’s financial advisors to potential bidders in March 2018 included a preliminary set of financial projections prepared by Aspen’s management. A summary of such financial projections that were set forth in the CIM is set forth below (expressed in millions of U.S. dollars):

The financial projections included in the CIM were updated by Aspen’s management after discussion with and approval by the Board in June 2018. The updates to the financial projections were primarily driven by, among other matters, improved projected underwriting results as a result of an anticipated reduction in natural catastrophe losses, projected performance improvement in insurance underwriting, projected expense reductions, projected improvement in results (other than those relating to catastrophic events) in certain business lines, and the impact of the discontinuation of the international professional indemnity, marine hull and aviation insurance business lines at Lloyd’s of London due to their limited contribution and volatility and the views of Aspen’s senior management and the Board that they should be discontinued as part of Aspen’s long-term strategic plan. The updated financial projections were made available to the remaining bidders on June 10, 2018. The following is a summary of the updated financial projections (expressed in millions of U.S. dollars):

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The following table represents the total estimated future dividends and net share repurchases for Aspen over a period of thirty-six months from January 1, 2018 to December 31, 2020 (expressed in millions of U.S. dollars):

The projections of dividends reflect projections of Aspen’s distributable cash flow to Aspen’s ordinary shareholders for the periods presented based on Aspen’s stand-alone financial plan and capital management policy and may not be indicative of aggregate net cash flows generated by Aspen or the amount of cash potentially available to Aspen to return to Aspen’s ordinary shareholders.

Financing

Aspen, Parent and Merger Sub estimate that the total amounts of funds required to complete the merger and pay related fees and expenses is approximately $2,600,000,000, for which Parent has obtained equity investment commitments under the equity commitment letter from the Apollo Funds.

The consummation of the merger is not conditioned upon receipt of any financing. Pursuant to the merger agreement, Parent and Merger Sub have represented that Parent and Merger Sub will have the required equity financing, in an amount sufficient to (i) pay the aggregate merger consideration, (ii) pay all fees and expenses required to be paid by Parent in connection with the transactions contemplated by the merger agreement and (iii) satisfy all other payment obligations of Parent and the Company payable on the closing date of the merger.

Equity Commitment Letter

Parent has entered into the equity commitment letter with the Apollo Funds pursuant to which the Apollo Funds have committed, on a several but not joint basis, on the terms and subject to the conditions of the equity commitment letter, to purchase, or cause to be purchased, directly or indirectly, equity of Parent in an aggregate amount up to $2,600,000,000, or such lesser amount sufficient to fully fund the aggregate merger consideration pursuant to the merger agreement. The Apollo Funds are permitted to assign their aggregate commitment to one or more affiliates or one or more third-party co-investors, each of which is acquiring less than 10% of the equity securities of Parent or any of its subsidiaries and will not be granted a right to designate any member of the board of directors or other governing body of Parent or any of its subsidiaries; however, no such assignment will relieve the Apollo Funds of their obligations under the equity commitment letter.

Funding of the equity financing is subject to the conditions provided in the equity commitment letter, which include the satisfaction in full or waiver by Parent, on or before the closing of the merger, of all conditions precedent to Parent’s obligations set forth in the merger agreement (other than those conditions that by their nature, are to be satisfied at the closing of the merger, each of which is capable of being satisfied at the Closing). Subject to certain limitations, the obligations of each Apollo Fund to fund its portion of the equity financing under the equity commitment letter will terminate upon the earliest to occur of:

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Aspen is an express third party beneficiary of the equity commitment letter, for the purpose of, in accordance with the terms and conditions of the merger agreement, seeking specific performance of the Apollo Funds’ obligation to fund the equity commitment to Parent (as described in the section entitled “The Merger Agreement—Terms of the Merger Agreement—Specific Performance” beginning on page 37 of this proxy statement).

Effective Time of Merger

Subject to Parent’s ability to delay closing in certain circumstances to determine the amount, if any, of net CAT losses, the closing of the merger will occur on the third business day following the satisfaction or waiver of all the closing conditions set forth in the merger agreement (described in the section of this proxy statement titled “The Merger Agreement—Closing; Effective Time”) (other than those conditions that by their nature are to be satisfied at the closing, but subject to the satisfaction or waiver of those conditions) or such other date and time as Aspen and Parent may agree in writing.

The merger will become effective upon the issuance of the certificate of merger by the Bermuda Registrar of Companies and at the time and date shown on such certificate of merger.

Interests of Aspen’s Directors and Executive Officers in the Merger

In considering the recommendation of the Board that you vote to approve the merger agreement and the merger, you should be aware that, aside from their interests as Aspen shareholders, Aspen’s directors and executive officers have interests in the merger that are different from, or in addition to, those of other Aspen shareholders generally. Members of the Board were aware of and considered these interests to the extent such interests existed at the time, among other matters, in evaluating and negotiating the merger agreement and the merger, and in recommending to the Aspen shareholders that the merger agreement and the merger be approved. Aspen’s shareholders should take these interests into account in deciding whether to vote “FOR” the proposal to approve the merger agreement and the merger. These interests are described in more detail below, and certain of them are quantified in the narrative and the table below.

Treatment of Aspen Equity Awards

As described under “The Merger Agreement—Treatment of Aspen Equity Awards” below, equity-based awards held by Aspen’s directors and executive officers as of the effective time will be treated at the effective time as follows:

Performance Units. Each performance unit that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of performance units outstanding immediately prior to the effective time, (i) with respect to any portion of a performance unit award with a performance period that has been completed, the number of shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a performance unit award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

Phantom Shares. Each phantom share that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of phantom shares outstanding immediately prior to the

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effective time, (i) with respect to any portion of a phantom share award with a performance period that has been completed, the number of phantom shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a phantom share award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

RSU Awards. Each RSU granted under a company share plan that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to (i) the sum of (x) the merger consideration and (y) any accrued but unpaid dividend equivalents in respect of such RSU, multiplied by (ii) the number of ordinary shares subject to such RSU which had not previously been settled, less any applicable tax withholdings.

Quantification of Payments. Assuming for this purpose that the merger were completed on November 1, 2018 (the last practicable date before the filing of this proxy statement), the table below sets forth the number of unvested performance units, phantom shares and RSUs held by Aspen’s executive officers and non-employee directors and the estimated value that Aspen’s executive officers and non-employee directors can expect to receive for such equity awards at the effective time based on the per share merger consideration equal to $42.75.

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Retention Bonuses

Beginning on August 7, 2018, Aspen granted retention bonus letters to certain of its key employees, including the following executive officers: Mr. Cain, Mr. Cohen, Mr. Issavi, Mr. Kirk, and Mr. Schick. The maximum amount that Mr. Kirk is eligible to receive under his retention bonus letter is $2,000,000. The maximum amount the other four executive officers are eligible to receive under the retention bonus letters is $9,500,000 in the aggregate. The retention bonus is payable, for Mr. Kirk, on January 1, 2020, and for the other executive officers, upon the earlier to occur of (a) January 1, 2020 and (b) twelve (12) months following the effective time; provided, that, in each case, the applicable executive officer continues to satisfactorily perform his employment duties and remains employed with Aspen through the applicable date of payment. In connection with a covered termination of employment (i.e., in the event the applicable executive officer’s employment is terminated by Aspen for any reason other than gross misconduct prior to the payment date), the entire retention bonus will be paid to the executive officer in a lump sum within forty-five (45) days after the termination of employment, provided the executive officer executes and does not revoke a release of claims.

Potential Transaction Bonuses

Under the merger agreement, subject to approval by the Compensation Committee of the Board, Aspen may grant cash transaction bonuses to certain executive officers in connection with the merger. Depending on the size of the transaction bonus, Parent’s consent may also be required. If approved, such transaction bonuses are anticipated to be payable upon the completion of the merger, subject to the executive officer’s continued employment through, and performance in executing, the merger, in the sole discretion of the Compensation Committee of the Board. As of the date of this proxy statement, no such transaction bonuses have been approved or awarded. It is expected that the Compensation Committee of the Board will meet prior to closing to determine whether any such transaction bonuses will be awarded and the terms of any such bonuses.

Change of Control Agreements

Aspen or one of its affiliates has entered into change of control employment agreements and, with respect to Mr. Cohen, an employment agreement (collectively, the “change of control agreements”) with each of its executive officers. Each executive officer’s change of control agreement provides for certain severance payments and/or benefits if, during the two (2) year period following a change of control (or, in certain cases, prior to such change in control in the event that the executive officer reasonably demonstrates that such termination of employment arose in connection with or in anticipation of the change in control), the executive officer’s employment is terminated by the employer without “cause” or the executive officer resigns with “good reason,” in each case, as defined in the change of control agreement, which termination we refer to as a qualifying termination. For purposes of each of the change of control agreements, the merger will constitute a change of control. The following is a summary of the severance payments and/or benefits that would be provided to each of our executive officers, including our named executive officers, in connection with a qualifying termination.

In the case of Mr. O’Kane, the severance payment would be equal to (i) the average bonus paid or payable to Mr. O’Kane in respect of the last three (3) full fiscal years, pro-rated based on the number of days in the fiscal year in which the qualifying termination occurs through the date of termination, plus (ii) three times the sum of (x) the current base salary rate and (y) the average bonus paid or payable to Mr. O’Kane in respect of the last three (3) full fiscal years. On October 1, 2018, Aspen announced that Mr. O’Kane will step down from his position as Chief Executive Officer and director of Aspen on or shortly following the closing of the merger. Apollo has informed Aspen that it anticipates that Mark Cloutier, who currently serves as executive chairman of Brit Ltd., will serve as Aspen’s Chief Executive Officer following the closing of the merger.

In the case of Messrs. Aman, Cain, Cohen, Issavi, Kirk, and Schick and Mses. Brown and Vacher, the severance payment would be equal to (i) the average bonus paid or payable to the applicable executive in respect of the last three (3) full fiscal years, pro-rated based on the number of days in the fiscal year in which the qualifying termination occurs through the date of termination, plus (ii) two times the sum of (x) the applicable executive’s current base salary rate and (y) the average bonus paid or payable to the applicable executive in respect of the last three (3) full fiscal years.

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In addition, each executive officer would be entitled to: (i) continued health and welfare benefits for one (1) year (or, in certain cases, a lump sum cash payment equal to the value of such benefit), (ii) the additional contributions the Company would have made on the executive officer’s behalf in the pension and retirement plans in which the executive officer participates plus the additional amount of any benefit the executive officer would have accrued under any excess or supplemental retirement plan in which the executive officer participates, in each case, had the executive officer’s employment continued for twelve (12) months following termination (or, in the event that contribution or participation limits would prevent the executive officer from receiving the full value of those benefits, a cash payment equal to any portion of benefits that cannot be so provided), (iii) except for Mr. Schick, fees for outplacement services (not to exceed $40,000) and (iv) accelerated vesting of any then-outstanding equity awards, with any performance conditions relating to these equity awards deemed to have been satisfied at the greater of target performance levels and actual performance.

Mr. Issavi’s change of control agreement contains a “Section 280G best net after-tax” provision, which provides that, if the total payments to Mr. Issavi under the agreement would exceed the applicable threshold under Section 280G of the Internal Revenue Code of 1986, as amended (the “Code”) then those payments will be reduced to the applicable Section 280G threshold to avoid the imposition of excise taxes under Section 4999 of the Code in the event, and only to the extent, such reduction would result in a better after-tax result for Mr. Issavi.

For an estimate of the amounts that would be payable to each of the Company’s named executive officers under the change of control agreements in connection with the merger, see “ —Quantification of Payments and Benefits to Aspen’s Named Executive Officers” below. The estimated amount that would be payable to Aspen’s seven other executive officers who are not named executive officers under the change of control agreement in connection with the merger is $11,227,728 in the aggregate.

Quantification of Payments and Benefits to Aspen’s Named Executive Officers

The table below, along with its footnotes, is intended to provide the information required by Item 402(t) of Regulation S-K regarding the amount of compensation for each of Aspen’s named executive officers that is based on or otherwise related to the merger, and assumes, among other things, that each named executive officer will experience a termination in connection with the change of control (or, if otherwise indicated below, a qualifying termination), as indicated below, immediately following the consummation of the merger. This merger-related compensation is subject to a non-binding advisory vote of Aspen shareholders, as set forth in Proposal 3 to this proxy statement. See the Section entitled “Proposal 3—Approval of the Compensation Advisory Proposal” on page 109.

Please note that the amounts described and quantified below are estimates based on multiple assumptions (including assumptions described in this proxy statement) that may or may not actually occur or be accurate on the relevant date and do not reflect certain compensation actions that may occur before the effective time. Some of the assumptions are based on information not currently available and, as a result, the actual amounts, if any, to be received by a named executive officer may differ in material respects from the amounts set forth below. For purposes of calculating the amounts included in the table below, we have assumed November 1, 2018 as the closing date of the merger and a termination of each named executive officer’s employment on November 1, 2018 immediately following the effective time. The relevant price per share is $42.75 per ordinary share, which is the fixed price per share to be received by Aspen’s shareholders as merger consideration in respect of their ordinary shares. See the section of this proxy statement titled “The Merger—Interests of Aspen’s Directors and Executive Officers in the Merger” beginning on page 54 for a detailed discussion on the interests of Aspen’s directors and

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executive officers in the merger. Amounts originally denominated in British Pounds have been converted into U.S. Dollars at the exchange rate of £1 to $1.3012 (i.e., the exchange rate on November 1, 2018 rounded to four decimal places). All dollar amounts set forth below have been rounded to the nearest whole number.

Golden Parachute Compensation

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Dividends, Distributions and Share Repurchases

Aspen customarily pays a quarterly cash dividend on the ordinary shares. Under the terms of the merger agreement, Aspen is restricted from declaring and paying regular quarterly dividends prior to the effective time.

Regulatory Clearances Required for the Merger

Each of the parties has agreed, upon the terms and subject to the conditions set forth in the merger agreement, to use its reasonable best efforts to take, or cause to be taken, all actions, and to do, or cause to be done, and to assist and to cooperate with the other parties in doing, all things necessary, proper or advisable to fulfill all conditions to the closing of the merger applicable to such party and to consummate and make effective the merger and the transactions contemplated by the merger agreement and the statutory merger agreement in the most expeditious manner reasonably practicable.

Such obligations will not require Parent or any of its affiliates to take any action, including entering into any consent decree, hold separate order or other arrangement, (i) that would, or would reasonably expected to have, a material adverse effect on the business, results of operations, or financial condition of (1) Aspen and its subsidiaries, taken as a whole, or (2) Parent or any of its affiliates (provided that, for this purpose, that the business and the financial condition, results of operations and other financial metrics of Parent or any of its affiliates that is of a smaller scale than Aspen and its subsidiaries, taken as a whole, is deemed to be of the same scale as those of Aspen and its subsidiaries, taken as a whole), (ii) relating to the contribution of capital, or any guaranty, keep-well, capital maintenance or similar arrangement, by Parent or any of its affiliates (other than Aspen and its subsidiaries) to or of Aspen or any of its subsidiaries or any restrictions on dividends or distributions that, in any case, has or would reasonably be expected to have a non-de minimis adverse economic impact on Parent or any of its affiliates or (iii) that requires or involves any adverse deviation in any material respect from any key term of the summary business plan with respect to Aspen and its insurance subsidiaries in connection with the merger (as described in the section of this proxy statement titled “The Merger Agreement—Efforts to Complete the Merger”).

Antitrust

Under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the “HSR Act”), Aspen and Parent cannot consummate the merger until Aspen and Parent have notified the Department of Justice’s Antitrust Division (the “Antitrust Division”) and the Federal Trade Commission (the “FTC”) of the merger and furnished them with certain information and materials relating to the merger and the applicable waiting period has terminated or expired. The termination or expiration of the waiting period means the parties have satisfied the regulatory requirements under the HSR Act. Aspen and Parent filed the required notifications with the Antitrust Division and the FTC on September 25, 2018 and early termination of the waiting period was granted effective October 2, 2018.

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Both Aspen and Apollo operate in the European Union. The EU Merger Regulation requires notification of and approval by the European Commission of mergers or acquisitions involving parties with worldwide and European Union sales exceeding given thresholds. The European Commission has an initial period of twenty-five (25) working days after its receipt of the notification to issue its decision (“Phase I”). The European Commission may extend this Phase I period to thirty-five (35) working days, if, within the first twenty (20) working days after submission of the notification, the parties propose remedies to address any competition concerns identified by the European Commission. The European Commission may open an extended investigation, which extends Phase I by up to ninety (90) working days, and can be extended to 105 working days, if remedies are offered after the 55th working day or to 110 working days by request of the parties or by the European Commission with consent of the parties. The merger cannot be consummated until after the European Commission has issued its clearance decision. In accordance with applicable best practices of the European Commission on merger control proceedings, Parent filed the first draft of the required notification with the European Commission on November 2, 2018 and is currently planning to file the final version of the required notification by the end of November 2018.

Merger control filings are also required in Chile, Turkey, and South Africa. Pursuant to Chilean Protection of Free Competition Act, the merger cannot be consummated until after the Chilean Competition Authority has issued its clearance decision and the Chilean Competition Authority has 70 calendar days after its receipt of the notification to issue its decision. Under Turkish Law on Protection of Competition, the merger cannot be consummated until after the Turkish Competition Board has issued its clearance decision or the relevant waiting periods have expired without the issuance of a decision, and the Turkish Competition Authority has 30 calendar days after its receipt of the notification, which can be extended by 15 days, to issue its decision. Pursuant to the South African Competition Act, the merger cannot be consummated until after the South African Competition Authority has issued its clearance decision or the relevant waiting periods have expired without the issuance of a decision, and the South African Competition Authority has 20 business days after its receipt of the notification to issue its decision. Parent filed in Turkey on October 26, 2018, in South Africa on November 2, 2018, and is planning on filing in Chile by the third week of November 2018.

Insurance and Other Regulatory Matters

The insurance laws and regulations of all fifty (50) U.S. states and the District of Columbia generally require that before the acquisition of control of an insurance company may occur, either through the acquisition of or merger with the insurance company or a holding company of that insurance company, the acquiring party must obtain approval from the insurance regulator of the insurance company’s state of domicile. In addition, many U.S. state insurance laws require prior notification to state insurance regulatory authorities of an acquisition of control of a non-domiciliary insurance company doing business in that state if the acquisition would result in specified levels of market concentration. While these prior notification statutes do not authorize the state insurance regulatory authorities to disapprove the acquisition of control, they authorize regulatory action in the affected state, including requiring the insurance company to cease and desist from doing certain types of business in the affected state or denying an application for a license to do business in the affected state, if particular conditions exist, such as the substantially lessening of competition in any line of business in such state.

Applications or notifications in connection with the merger or the changes in control of various subsidiaries of Aspen and Parent that may be deemed to occur as a result of the merger have been filed, pursuant to the merger agreement, with various U.S. state regulatory authorities. Apollo filed an application for approval of the change of control with the Texas Department of Insurance on October 5, 2018, and with the North Dakota Insurance Department on November 1, 2018.

Applications for approval or notifications to regulators have also been filed with certain non-U.S. regulatory authorities, including but not limited to, the Bermuda Monetary Authority, the UK Prudential Regulation Authority, the UK Financial Conduct Authority, Lloyd’s of London, the Australian Treasury, the Jersey Financial Services Commission, the Dubai Financial Services Authority, the Central Bank of Ireland, the Italian Institute for the Supervision of Insurance, the Monetary Authority of Singapore, the Swiss Financial Market Supervisory Authority and the Office of the Financial Institutions of Canada.

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Although Aspen and Parent do not expect these regulatory authorities to raise any significant concerns in connection with their review of the merger, there is no assurance that Aspen and Parent will obtain all required regulatory approvals on a timely basis, if at all, or that these approvals will not include a restriction, limitation or condition that would trigger a burdensome condition, which, in such case, would permit Parent to refuse to close the transactions contemplated by the merger agreement and consummate the merger.

Other than the approvals and notifications described above, neither Aspen nor Parent is aware of any material regulatory approvals required to be obtained, or waiting periods required to expire, after the making of a filing. If the parties discover that other approvals or filings and waiting periods are necessary, they will seek to obtain or comply with them, although, as is the case with the regulatory approvals described above, there can be no assurance that they will be obtained on a timely basis, if at all.

Payment of Merger Consideration and Surrender of Share Certificates

Paying Agent

Prior to the closing date, Parent will designate a paying agent reasonably acceptable to Aspen for the payment and delivery of the aggregate merger consideration. Prior to the effective time, Parent will deposit or cause to be deposited with the paying agent cash in an amount sufficient to pay the aggregate merger consideration.

Payment Process

As soon as practicable, but in no event later than three (3) business days after the effective time, the surviving company or Parent will cause the paying agent to mail a letter of transmittal (in a form subject to Aspen’s reasonable approval) to each holder of a share certificate, as well as instructions regarding the procedures by which holders of share certificates may receive the merger consideration. Upon the completion of such applicable procedures and the surrender of such holder’s share certificates or without any action by holders of book-entry shares, the paying agent will deliver to the holder the merger consideration that the holder is entitled to receive and the share certificates or book-entry shares will be canceled immediately. No interest will be paid or accrue on the merger consideration.

Unregistered Transferees

If any merger consideration is to be paid to a person or entity other than the person or entity in whose name the surrendered Aspen certificate is registered, it will be a condition to the payment of such merger consideration to such transferee that the surrendered certificate be properly endorsed or will otherwise be in proper form for transfer and the transferee will have established that any transfer and other required taxes has been paid or is not applicable.

Withholding

Parent, the surviving company or the paying agent, as applicable, will be entitled to deduct and withhold from the amounts otherwise payable pursuant to the merger agreement such amounts as are required to be deducted and withheld with respect to the making of payments under any provision of applicable tax or other law or pursuant to any Company plan. Amounts so withheld and paid over to the appropriate governmental authority will be treated for all purposes of the merger agreement as having been paid to the Aspen shareholder in respect of which such deduction and withholding was made.

Delisting and Deregistration of Aspen Shares

If the merger is completed, the ordinary shares will be delisted from the NYSE and the BSX and deregistered under the Exchange Act.

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At the effective time, each preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged. The preference shares will remain listed on the NYSE and registered by Aspen under the Exchange Act immediately after the merger. Parent may decide, following the merger, to delist the preference shares from the NYSE, deregister such preference shares under the Exchange Act or take other action with respect to the preference shares.

Dissenters’ Rights of Appraisal for Aspen Shareholders

Any dissenting shareholder who did not vote in favor of the merger proposal and who is not satisfied that it has been offered fair value for its Aspen shares may, within one month of the giving of the notice calling the special general meeting, apply to the Bermuda Court to appraise the fair value of its Aspen shares, provided that such shareholder fully complies with the requirements of the Companies Act.

FOR THE AVOIDANCE OF DOUBT, A FAILURE OF A DISSENTING SHAREHOLDER TO AFFIRMATIVELY VOTE AGAINST THE MERGER PROPOSAL WILL NOT CONSTITUTE A WAIVER OF ITS RIGHT TO HAVE THE FAIR VALUE OF ITS ASPEN SHARES APPRAISED, PROVIDED THAT SUCH DISSENTING SHAREHOLDER DID NOT VOTE IN FAVOR OF THE MERGER PROPOSAL.

The Bermuda Court can determine the fair value to be greater than, less than, or equal to the merger consideration. Where the Bermuda Court has appraised the fair value of any Aspen shares and the merger has been consummated prior to the appraisal (as is anticipated) then, within one month of the Bermuda Court appraising the value of the Aspen shares, if the value received by any dissenting shareholder for its Aspen shares is less than the value of its Aspen shares as appraised by the Bermuda Court, the surviving company shall pay to such dissenting shareholder the difference between the value received and the value appraised by the Bermuda Court.

There is no right of appeal from an appraisal by the Bermuda Court. The costs of any application to the Bermuda Court to appraise the fair value of the Aspen shares shall be at the discretion of the Bermuda Court.

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THE MERGER AGREEMENT

The following describes the material provisions of the merger agreement, a composite conformed copy of which is included as Annex A-1 to this proxy statement and incorporated by reference herein. The summary of the material provisions of the merger agreement below and elsewhere in this proxy statement is qualified in its entirety by reference to the merger agreement. This summary does not purport to be complete and may not contain all of the information about the merger agreement that is important to you. Aspen encourages you to read carefully the merger agreement in its entirety before making any decisions regarding the merger as it is the legal document governing the merger.

The merger agreement and this summary of its terms have been included to provide you with information regarding the terms of the merger agreement and is not intended to provide any factual information about Aspen or Parent. Factual disclosures about Aspen or Parent contained in this proxy statement or Aspen’s public reports filed with the SEC may supplement, update or modify the factual disclosures about Aspen or Parent contained in the merger agreement and described in the summary. The representations, warranties and covenants made in the merger agreement by Aspen, Parent and Merger Sub are qualified and subject to important limitations agreed to by Aspen, Parent and Merger Sub in connection with negotiating the terms of the merger agreement. In particular, in your review of the representations and warranties contained in the merger agreement and described in this summary, it is important to bear in mind that the representations and warranties were negotiated with the principal purpose of allocating risk between the parties to the merger agreement, rather than establishing matters as facts, and may be subject to subsequent waiver or modification. The representations and warranties may also be subject to a contractual standard of materiality that may be different from that generally relevant to shareholders or applicable to reports and documents filed with the SEC, and in some cases are qualified by confidential disclosures that were made by each party to the other, which disclosures are not reflected in the merger agreement or otherwise publicly disclosed. The representations and warranties in the merger agreement will not survive the completion of the merger. Moreover, information concerning the subject matter of the representations and warranties may have changed since the date of the merger agreement and subsequent developments or new information qualifying a representation or warranty may have been included or incorporated by reference into this proxy statement. For the foregoing reasons, the representations, warranties and covenants or any descriptions of those provisions should not be read alone, but instead should be read together with the information provided elsewhere in this proxy statement and in the documents incorporated by reference into this proxy statement. See the section of this proxy statement titled “Where You Can Find Additional Information” beginning on page 116.

The Merger

On the terms and subject to the conditions of the merger agreement and the statutory merger agreement, and in accordance with the applicable provisions of the Companies Act, at the effective time, Merger Sub will merge with and into Aspen, the separate corporate existence of Merger Sub will cease and Aspen will survive the merger as a wholly-owned subsidiary of Parent.

Effects of the Merger

The merger agreement provides that, at the effective time, each ordinary share issued and outstanding immediately prior to the effective time (other than ordinary shares owned by Aspen as treasury shares, owned by any subsidiary of Aspen or owned by Parent, Merger Sub or any subsidiary of Parent, which will be canceled as set forth in the merger agreement) will be converted into the right to receive $42.75 in cash, without interest and less any required withholding tax. All such ordinary shares will no longer be outstanding and will be canceled and cease to exist and each holder of a certificate previously evidencing any ordinary shares or uncertificated ordinary shares represented by book-entry will cease to have any rights with respect to those shares, except the right to receive the merger consideration.

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At the effective time, Parent will become the sole owner of Aspen’s ordinary shares. Therefore, current Aspen ordinary shareholders will cease to have direct or indirect ownership interests in Aspen or rights as Aspen ordinary shareholders, will not participate in any future earnings or growth of Aspen, will not benefit from any appreciation in value of Aspen and will not bear the future risks of Aspen’s operations.

At the effective time, each 5.95% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged.

At the effective time, each 5.625% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged.

Following completion of the merger, Aspen’s ordinary shares will be delisted from the NYSE and the BSX and deregistered under the Exchange Act. As a result, there will be no public market for Aspen’s ordinary shares. This will make certain provisions of the Exchange Act, such as the requirement of furnishing a proxy or information statement in connection with shareholders’ meetings, no longer applicable to Aspen. After the effective time, Aspen will also no longer be required to file periodic reports with the SEC on account of Aspen’s ordinary shares. However, Aspen will continue to make securities filings with respect to its publicly-held preference shares to the extent such filings are required under SEC regulations following the completion of the merger. Parent may decide, following the merger, to delist the preference shares from the NYSE, to deregister such preference shares under the Exchange Act or to take other action with respect to the preference shares.

The directors of Merger Sub immediately prior to the effective time will be the initial directors of Aspen as the surviving company until their earlier death, resignation or removal or until their respective successors are duly elected and qualified. Other than Aspen’s Chief Executive Officer, who will resign on or shortly after closing, the officers of Aspen immediately prior to the effective time will be the initial officers of Aspen as the surviving company until their earlier death, resignation or removal or until their respective successors are duly appointed and qualified.

Closing; Effective Time

Subject to Parent’s ability to delay closing in certain circumstances to determine the amount, if any, of net CAT losses, the closing of the merger will occur on the third business day following the satisfaction or waiver of the closing conditions set forth in the merger agreement (other than those conditions that by their nature are to be satisfied at the closing, but subject to the satisfaction or waiver of those conditions) or at such other date and time as Aspen and Parent may agree in writing. See the section of this proxy statement titled “The Merger Agreement—Conditions to Completion of the Merger” beginning on page 66 for further discussion on the conditions to the closing of the merger.

Catastrophe Events.

If, as of the date on which the closing would otherwise occur under the merger agreement, one or more CAT events (as described below) has occurred between July 1, 2018 and January 31, 2019 (or the closing date, if earlier), and Parent, having determined reasonably and in good faith and after taking into account all relevant information reasonably available, including available industry loss estimates from reliable sources, Aspen’s own estimates and modeling with respect to losses arising out of such CAT events (or Aspen’s representations regarding such estimates and modeling, as applicable), the amount of time that has passed since the occurrence of such CAT events and relevant historical experience regarding events that were similar to such CAT events (which we refer to as “acting in accordance with the agreed standard”), believes that the aggregate amount of all (i) losses and allocated loss adjustment expenses incurred and reinstatement premiums paid or payable with respect to ceded reinsurance or retrocessional treaties plus (ii) loss and allocated loss adjustment expenses

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reserves established (based on Aspen’s historical reserving methodologies and information available as of the applicable date of determination) less (iii) reinsurance and other recoverables that are not doubtful or reasonably likely to be uncollectible less (iv) reinstatement premiums due (and not doubtful or reasonably likely to be uncollectible) or received with respect to assumed reinsurance or retrocessional treaties (“net CAT losses”) arising from such CAT events may reasonably be likely to exceed $350,000,000 but that more time is needed to determine more accurately the amount of such net CAT losses, then Parent may delay the closing for up to thirty (30) days. Parent may only exercise this right to delay the closing once. If, at or after the end of the 30-day period, all conditions to the closing have been satisfied or waived, then the closing will occur on the first business day after the end of such 30-day period unless Parent has exercised its determination right (as defined below).

Conditions to Completion of the Merger

Catastrophe Events – Delivery of Loss Report.

If, as of any time on or prior to March 3, 2019, one or more CAT events has occurred between July 1, 2018 and January 31, 2019, and Parent, acting in accordance with the agreed standard, believes that net CAT losses arising from such CAT events exceed $350,000,000, then it may exercise its determination right to initiate a process to determine the amount of net CAT losses. If Parent exercises its determination right, Aspen, acting in accordance with the agreed standard, will deliver a written loss report setting forth Aspen’s reasonable and good faith estimated calculation of net CAT losses as of the end of the month immediately preceding the month in which the determination right was exercised. Parent will have a ten (10) business day period to review the loss report and the calculations set forth therein and, if Parent, acting in accordance with the agreed standard, disagrees with Aspen’s loss report (including any amount or computation set forth therein) on the basis that the loss report is inaccurate and that, if the loss report were accurate, net CAT losses as reflected on such loss report would be greater than $350,000,000, it may initiate during the review period a dispute resolution process, which may involve an independent actuary, to resolve disputed items in the loss report. If, after the loss report has been finally determined, net CAT losses are determined to be in excess of $350,000,000, Parent will have the ability to terminate the agreement within ten (10) business days after the loss report has been finally determined.

Parent may not exercise its determination right more than once. If, after the loss report has been finally determined, net CAT losses are determined not to be in excess of $350,000,000, Parent will not have the ability to terminate the merger agreement as a result of net CAT losses.

For purposes of the merger agreement, a “CAT event” is any of the following events that first occurs between July 1, 2018 through January 31, 2019:

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Mutual Conditions

The obligations of Aspen, Parent and Merger Sub to effect the merger are subject to the satisfaction (or waiver by the parties, if permissible under applicable law) of the following conditions:

Parent and Merger Sub Conditions

Parent’s and Merger Sub’s obligations to consummate the merger are subject to the satisfaction (or waiver by Parent and Merger Sub, if permissible under applicable law) of the following additional conditions:

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Aspen Conditions

Aspen’s obligations to consummate the merger are subject to the satisfaction (or waiver by Aspen, if permissible under applicable law) of the following additional conditions:

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Material Adverse Effect

For the purposes of the merger agreement, a “material adverse effect” will be deemed to occur if any effect, change, event, circumstance, state of facts, development or occurrence, individually or in the aggregate, has had, or is reasonably expected to have, a material adverse effect on the business, operations, results of operations, assets and liabilities (considered together), or the financial condition of Aspen and its subsidiaries, taken as a whole.

However, when determining whether a material adverse effect has occurred, none of the following will be considered except as expressly noted below:

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Certain effects, changes, events or occurrences listed in each of the first, second, fourth, fifth and ninth bullets above may be taken into account in determining whether a material adverse effect has occurred with respect to Aspen if, but only to the extent, any such effect, change, event or occurrence has a disproportionate adverse effect on Aspen and its subsidiaries, taken as a whole, relative to other participants engaged primarily in the industries and in the geographic regions or product markets in which Aspen and its subsidiaries operate or underwrite insurance or reinsurance. In such case, only the disproportionate effect or effects may be taken into account when determining whether a material adverse effect has occurred with respect to Aspen.

Parent Material Adverse Effect

For the purposes of the merger agreement, a “parent material adverse effect” will be deemed to occur if any effect, change, event, circumstance, state of facts, development or occurrence, individually or in the aggregate, would, or would reasonably be expected to prevent, delay, interfere with, hinder, or impair, in each case, in any material respect (i) the consummation by Parent or Merger Sub of any of the transactions contemplated by the merger agreement on a timely basis or (ii) the compliance by Parent or Merger Sub with its obligations under the merger agreement.

Efforts to Obtain Required Shareholder Approvals

Unless the merger agreement has been earlier terminated, including pursuant to Aspen’s right to terminate the merger agreement to enter into an alternative acquisition agreement (see the section of this proxy statement titled “The Merger Agreement—No Solicitation of Takeover Proposals; Adverse Recommendation Change; Alternative Acquisition Agreements” below), Aspen has agreed to hold a special general meeting of its shareholders and to use its reasonable best efforts to obtain the requisite approval of Aspen’s shareholders for the bye-law amendment proposal and the merger proposal.

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No Solicitation of Takeover Proposals; Adverse Recommendation Change; Alternative Acquisition Agreements

No Solicitation of Takeover Proposals

Aspen is prohibited from taking certain actions, summarized in detail below, relating to takeover proposals. In this proxy statement, and in the merger agreement, a “takeover proposal” means any inquiry, proposal or offer from any person or group other than Parent and its subsidiaries, relating to a:

Any transaction meeting the above conditions, whether effected in a single transaction or through a series of related transactions, or directly or indirectly, is a “takeover proposal.”

Specifically, Aspen has agreed that it will, and will cause each of its subsidiaries to, and its and their respective directors, officers and employees to, and will use its reasonable best efforts to cause its other representatives, as applicable, to immediately cease any solicitation, knowing encouragement, discussions or negotiations of or with any persons that may be ongoing on or prior to August 27, 2018 with respect to any takeover proposal.

Aspen has also agreed that, from August 27, 2018 until earlier of the closing date and the date on which the merger agreement is terminated in accordance with its terms, it will not, and will cause each of its subsidiaries not to, and its and their respective directors, officers and employees not to, and will use its reasonable best efforts to cause its other representatives not to, directly or indirectly:

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Aspen has further agreed that it will, to the extent it has not previously done so prior to August 27, 2018, deliver a request to each person that executed a confidentiality agreement with Aspen during the eighteen month period prior to August 27, 2018 or has received non-public information from or on behalf of Aspen during such period, in either case, in connection with considering or making a takeover proposal to promptly return or destroy any non-public information previously furnished or made available to such person or any of its representatives on behalf of Aspen or representatives of Aspen. Notwithstanding the foregoing or anything else in the merger agreement to the contrary, Aspen may waive, and may choose not to enforce, any provision of any standstill or confidentiality agreement with any person that would prohibit such person from communicating confidentially a takeover proposal to the Board, if and only to the extent that the Board determines in good faith, after consultation with its financial advisors and outside legal counsel, that the failure to do so would be inconsistent with its fiduciary duties under applicable law.

The non-solicitation obligations summarized above do not prohibit Aspen or its representatives from contacting a person that has made a takeover proposal delivered to Aspen during the period between August 27, 2018 and the date Aspen shareholders approve the merger agreement that did not result from a material breach by Aspen of such non-solicitation provisions solely to clarify the terms and conditions of such takeover proposal or to request that any takeover proposal made orally be made in writing.

If the Board determines in good faith after consultation with its financial advisors and outside legal counsel that such takeover proposal constitutes or would reasonably be expected to lead to a takeover proposal superior to Parent’s, then Aspen and its representatives may (i) enter into a confidentiality agreement with and furnish information (including non-public information) about Aspen and its subsidiaries to the person or group of persons making the takeover proposal, and (ii) subsequently engage in or otherwise participate in discussions or negotiations with the person or group of persons making such takeover proposal.

If Aspen enters into a confidentiality agreement and furnishes information (including non-public information) to a person or group of persons making a takeover proposal, the merger agreement requires Aspen to promptly provide to Parent a copy of the confidentiality agreement and to concurrently provide Parent any information about Aspen or its subsidiaries that is provided to any person given such access that was not previously provided to Parent or its representatives.

Aspen has agreed to promptly notify Parent upon receipt of any takeover proposal (and in any event within twenty-four hours after receipt thereof). Aspen has also agreed to promptly disclose to Parent the material terms and conditions of such takeover proposal and the identity of the person or group of persons making such takeover proposal and unredacted copies of all proposals, offers, indications of interest, term sheets, or other material agreements and documents with respect thereto or that contain proposed terms of such takeover proposal (and communicate to Parent any material terms and conditions orally communicated to Aspen or its representatives in connection with such takeover proposal).

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Finally, Aspen has agreed to keep Parent reasonably informed of any material developments with respect to such takeover proposal on a prompt basis.

Adverse Recommendation Change; Termination of the Merger Agreement to Enter into an Alternative Acquisition Agreement

Except as described below, Aspen has agreed that neither its Board, nor any committee thereof, will:

If Aspen takes any of the above actions it will be deemed an “adverse recommendation change” and this proxy statement generally refers to any of such actions as an “adverse recommendation change.”

In addition, except as described below, Aspen has agreed that its Board will not authorize, cause or permit, or publicly propose to authorize, cause or permit, Aspen or any of its subsidiaries to execute or enter into any letter of intent, memorandum of understanding, agreement in principle, merger agreement, acquisition agreement, stock purchase agreement, asset purchase agreement, option agreement, amalgamation agreement or other agreement related to any takeover proposal, other than a confidentiality agreement with the person or persons making the takeover proposal, or requiring, directly or indirectly, Aspen to abandon, terminate or fail to consummate the transactions contemplated by the merger agreement.

However, prior to the date Aspen shareholders approve the merger agreement, in response to a superior proposal that has not been withdrawn, the Board may make an adverse recommendation change or cause Aspen to terminate the merger agreement, pay to Parent the termination fee and enter into an alternative acquisition agreement to implement such superior proposal, if:

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For purposes of this proxy statement and the merger agreement, a “superior proposal” means a bona fide written takeover proposal with respect to Aspen

In addition, prior to the date Aspen shareholders approve the merger proposal, in response to an intervening event, the Board may make an adverse recommendation change if:

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For purposes of this proxy statement and the merger agreement, “intervening event” means a material effect, change, event, circumstance, state of facts, development or occurrence relating to Aspen and its subsidiaries, taken as a whole that:

However, the term “intervening event” does not include any effect, change, event, circumstance, state of facts, development or occurrence specifically related to the receipt, existence of or terms of a takeover proposal or any inquiry relating thereto.

As described in further detail in the section of this proxy statement titled “The Merger Agreement—Expenses and Termination Fees,” Aspen will be required to pay Parent a $82,935,000 termination fee, if:

Treatment of the 5.95% Fixed-to-Floating Rate Perpetual Non-Cumulative Preference Shares

Subject to the rights of dissenting shareholders, each 5.95% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged. Following the merger, Parent may cause the surviving company to exercise any of its rights with respect to each 5.95% preference share issued and outstanding.

Treatment of the 5.625% Perpetual Non-Cumulative Preference Shares

Subject to the rights of dissenting shareholders, each 5.625% preference share issued and outstanding immediately prior to the effective time will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such preference share will remain unchanged. As with the 5.95% preference shares, following the merger Parent may cause the surviving company to exercise any of its rights with respect to each 5.625% preference share issued and outstanding.

Dissenting Shares

Assuming the requisite shareholder vote is obtained, Aspen shareholders who do not vote in favor of the merger at the special general meeting will, with respect to ordinary shares, receive the merger consideration, and with respect to preference shares, have their preference shares continue as preference shares of Aspen as the surviving company following the merger with the relative rights, terms and conditions of each such preference

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share remaining unchanged. Any dissenting shareholder will, in the event that the fair value of a dissenting share as appraised by the Bermuda Court under the Companies Act is greater than, (i) with respect to ordinary shares, the merger consideration, (ii) with respect to 5.95% preference shares, the value of their preference shares of the surviving company or (iii) with respect to 5.625% preference shares, the value of their preference shares of the surviving company, be entitled to receive such difference from Aspen as the surviving company by payment made within thirty (30) days after the final determination by the Bermuda Court of the “fair value” of such shares. If a dissenting shareholder fails to exercise, effectively withdraws or otherwise waives any right to appraisal, such dissenting shareholder’s shares, (i) if an ordinary share, will be canceled and converted as of the effective time into the right to receive the merger consideration, (ii) if a 5.95% preference share, will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such class of preference shares will remain unchanged or (iii) if a 5.625% preference share, will continue as a preference share of Aspen as the surviving company following the merger and the relative rights, terms and conditions of each such class of preference shares will remain unchanged. For a more complete description of the available appraisal rights, see the section of this proxy statement titled “The Merger—Dissenters’ Rights of Appraisal of Aspen Shareholders” beginning on page 63.

Under the merger agreement, Aspen has agreed to give Parent (i) written notice of any demands for appraisal of dissenting shares (or withdrawals thereof) and, to the extent Aspen has knowledge thereof, any applications to the Bermuda Court for appraisal of the fair value of the dissenting shares and (ii) to the extent permitted by applicable law, the opportunity to participate with Aspen in any settlement negotiations and proceeds with respect to any demands for appraisal under the Companies Act. Aspen will not, without the prior written consent of Parent, voluntarily make any payment with respect to, offer to settle or settle any such demands or applications, or waive any failure to timely deliver a written demand for appraisal or to timely take any other action to exercise appraisal rights in accordance with the Companies Act.

Treatment of Aspen Equity Awards

As of the effective time, each performance unit that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of performance units outstanding immediately prior to the effective time, (i) with respect to any portion of a performance unit award with a performance period that has been completed, the number of shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a performance unit award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

As of the effective time, each phantom share that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the merger consideration, less any applicable tax withholdings; provided that, for purposes of determining the number of phantom shares outstanding immediately prior to the effective time, (i) with respect to any portion of a phantom share award with a performance period that has been completed, the number of shares will be determined based on the actual level of performance achieved, and (ii) with respect to any portion of a phantom share award with a performance period that has not been completed, any applicable performance-based vesting requirements will be deemed to be achieved immediately prior to the effective time at target payout levels.

As of the effective time, each RSU that is outstanding immediately prior to the effective time will, to the extent not vested, become fully vested, and will be canceled and converted into the right to receive a lump-sum amount in cash, without interest, equal to the product of (i) the sum of (x) the merger consideration and (y) any accrued but unpaid dividend equivalents in respect of such RSU, multiplied by (ii) the number of Aspen common shares subject to such RSU which had not previously been settled, less any applicable tax withholdings.

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Treatment of Aspen ESPP

Aspen will take all actions necessary to cause the Aspen ESPP (i) not to commence an offering period to purchase ordinary shares that would otherwise begin after the end of any offering period in effect as of the date of the merger agreement, (ii) not to accept payroll deductions to be used to purchase ordinary shares under the Aspen ESPP after the end of any offering period in effect as of the merger agreement and (iii) to ensure that no new participants be permitted to participate in the Aspen ESPP and that the existing participants thereunder may not increase their elections with respect to any offering period in effect as of the date of the merger agreement. In addition, Aspen will take all actions necessary to cause the Aspen ESPP to terminate immediately after the purchases set forth in the following paragraph, if any, are completed and immediately prior to the effective time.

In the case of any outstanding purchase rights under the Aspen ESPP, (i) immediately prior to the effective time (x) any offering period under Aspen’s Employee Share Purchase Plan and the International Employee Share Purchase Plan will end and each participant’s accumulated payroll deduction will be used to purchase newly issued ordinary shares in accordance with the terms of Aspen’s Employee Share Purchase Plan or the International Employee Share Purchase Plan (as applicable) and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement, and (ii) prior to the effective time (x) Aspen will promptly take all actions necessary to enable and require participants in its 2008 Sharesave Scheme to utilize their accumulated payroll deduction to purchase newly issued ordinary shares in accordance with the terms of the 2008 Sharesave Scheme, such that there are no outstanding purchase rights thereunder as of the effective time and (y) such ordinary shares will be treated the same as all other ordinary shares in accordance with the merger agreement.

Efforts to Complete the Merger

Each of Parent, Merger Sub and Aspen has agreed, upon the terms and subject to the conditions set forth in the merger agreement, to, and to cause its subsidiaries to, and, with respect to Parent, to use its reasonable best efforts to cause its control persons under applicable law, if applicable, to, use its reasonable best efforts to fulfill all conditions to the closing of the merger applicable to such party and to consummate and make effective, in the most expeditious manner reasonably practicable, the merger and the transactions contemplated by the merger agreement and the statutory merger agreement. Specifically, such actions include:

In addition, each of the parties agreed to, and to cause their respective subsidiaries to, and, with respect to Parent, to use its reasonable best efforts to cause its control persons under applicable law, if applicable, to, use its reasonable best efforts to avoid each and every impediment under any applicable law that may be asserted by, or judgment, decree and order that may be entered with, any governmental authority with respect to the transactions contemplated by the merger agreement and the statutory merger agreement so as to enable the closing to occur in the most expeditious manner reasonably practicable. Specifically, such actions include using reasonable best efforts in:

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Burdensome Condition

The obligations of the parties described in this section “Efforts to Complete the Merger” will not require Parent or any of its affiliates to take or refrain from taking, or agree to take or refrain from taking, any action, including entering into any consent decree, hold separate order or other arrangement, or permit or suffer to exist any condition, limitation, restriction or requirement:

Furthermore, the provisions of the merger agreement do not obligate any party or its affiliates to take any action required by a governmental authority which is not conditioned upon the closing of the merger.

Regulatory Filings

The section of this proxy statement titled “The Merger—Regulatory Clearances Required for the Merger” beginning on page 60 includes a description of the material regulatory approvals required for the completion of the merger that are referenced above.

Aspen has waived the obligation for Parent to file, or use its reasonable best efforts to cause each of its control persons under applicable law, if applicable, to file, and pay all necessary filing fees for the following required forms, applications, and notification filings with the governmental authorities listed below within twenty (20) business days after August 27, 2018 to allow the filings to have been made by October 5, 2018 other than the filing with the North Dakota Insurance Department and the Monetary Authority of Singapore, which the waiver allows to be made by November 1, 2018:

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Aspen and Parent have agreed that each will make any necessary, proper, or advisable registrations, draft filings and notices under non-U.S. Antitrust Laws within twenty (20) business days after Aspen provides the information necessary to determine what filings are required under any applicable antitrust laws.

Information

In connection with the efforts described in this section “Efforts to Complete the Merger,” each party has agreed:

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Aspen and Parent have further agreed that each will not be obligated to provide information to a third party if a party to the merger agreement determines in its reasonable judgment that (i) doing so would violate applicable law or a contract, agreement, privilege or obligation of confidentiality owing to a third party, jeopardize the protection of an attorney-client privilege or expose such party to risk of liability for disclosure of sensitive or personal information or (ii) such information is not directly related to the transactions contemplated by the merger agreement and the statutory merger agreement.

Termination of the Merger Agreement

The merger agreement may be terminated and the transactions contemplated by the merger agreement abandoned at any time prior to the effective time, whether before or after receipt of the requisite approvals of the Aspen shareholders (except as otherwise noted), under any of the following circumstances:

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Upon termination of the merger agreement in accordance with its terms by a party, written notice will be given to the other parties specifying the provision thereof pursuant to which such termination is made and the merger agreement will become null and void without liability on the part of any party or its directors, officers or affiliates, other than, with respect to any party to the merger agreement, the obligations pursuant to certain provisions that will survive the termination of the merger agreement. In addition, nothing will relieve any party to the merger agreement from liability for any willful breach of any provision set forth in the merger agreement (in an amount that does not exceed the reverse termination fee, in the case of Parent).

Triggering Event

For the purposes of the merger agreement, a “triggering event” is deemed to occur when, prior to the closing date, Aspen receives a clear indication from a rating agency after a discussion with the rating agency that it intends to downgrade the rating of Aspen or any of its subsidiaries in the near-term and (x) Aspen, without the consent of Parent, takes any commercially reasonable actions that the Board reasonably determines are reasonably necessary to avoid the ratings downgrade and the taking of such action causes, or would reasonably be expected to cause, a significant adverse economic consequence for Aspen and its subsidiaries, taken as a whole, or increases in any respect the aggregate merger consideration payable to Aspen shareholders, or

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(y) Aspen takes, or refrains from taking, without the consent of Parent, any commercially reasonable actions that the Board reasonably determines are reasonably necessary to avoid the ratings downgrade and such action or failure is any the following:

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Expenses and Termination Fees

Generally, all fees and expenses incurred in connection with the merger agreement and the transactions contemplated by the merger agreement and the statutory merger agreement will be paid by the party incurring or required to incur such fees and expenses, whether or not the merger is consummated.

Aspen will be obligated to pay a termination fee of $82,935,000 (the “termination fee”) to Parent under the following circumstances:

In no event will Aspen be required to pay the termination fee more than once.

Parent will be obligated to pay a reverse termination fee of $165,870,000 (the “reverse termination fee”) to Aspen under the following circumstances:

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In no event will Parent be required to pay the reverse termination fee more than once.

In the event Parent fails to effect the merger when required pursuant to the terms and conditions of the merger agreement, then Aspen’s right to seek (but never to receive more than one of) (i) a decree or order of specific performance or any injunction or injunctions or other equitable relief, if and to the extent permitted by the terms of the merger agreement described below under the section of this proxy statement titled “The Merger Agreement—Remedies; Specific Enforcement,” (ii) the termination of the merger agreement pursuant to the provisions described above and seek monetary damages solely on the basis of Parent’s actual, knowing fraud with the intent to deceive Aspen, regarding Parent’s representations and warranties, or (iii) the termination of the merger agreement pursuant to the provision described above in the last bullet under Aspen’s termination rights in the section of this proxy statement titled “The Merger Agreement—Termination of the Merger Agreement,” which requires Parent to pay Aspen a reverse termination fee, if, as and when required pursuant to the terms of the merger agreement, and reimbursement of Aspen’s enforcement expenses and reimbursement for certain expenses and costs incurred by Aspen pursuant to the terms and conditions of the merger agreement will be the sole and exclusive remedy of Aspen, its affiliates and their respective shareholders and representatives and any other person against Parent, its affiliate and their respective related parties. The amount of the enforcement expenses and expense reimbursement payable by Parent and its affiliates and their respective related parties in the circumstances described above will not exceed $1,500,000. In no event will Parent and its affiliates and their respective related parties have any liability under the merger agreement or otherwise for an amount in excess of the amount of the reverse termination fee and the amounts due for enforcement costs and expense reimbursement described in the previous sentence.

Conduct of Business Pending the Completion of the Merger

Aspen has agreed to certain covenants in the merger agreement restricting the conduct of its business between August 27, 2018 and the earlier of the closing or the termination of the merger agreement. In general, except as required by applicable law, as required or contemplated by the terms of the merger agreement, as may have been previously disclosed in writing to Parent as provided in the merger agreement or with the prior written consent of Parent (such consent not to be unreasonably withheld, conditioned or delayed), (i) Aspen will, and will cause its subsidiaries to, use reasonable best efforts to carry on its business in all material respects in the ordinary course of business consistent with past practice, (ii) Aspen will, and will cause its subsidiaries to, use reasonable best efforts to preserve its and its subsidiaries’ business organizations and material assets substantially intact, keep available in all material respects the services of its current officers, employees and consultants and preserve its goodwill and existing relationships with material customers, brokers, reinsurance providers, regulators, officers, employees, and other persons with whom Aspen or any of its subsidiaries have significant business relationships and (iii) Aspen will not, and will not permit any of its subsidiaries to: