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Via Facsimile and U.S. Mail Mail Stop 4720                                                                                                   December 23, 2009  Christopher O’Kane Chief Executive Officer Aspen Insurance Holdings Limited Maxwell Roberts Building 1 Church Street Hamilton, Bermuda  HM 11
Re: Aspen Insurance Holdings Limited
 Form 10-K for Fiscal Year Ended December 31, 2008
 Form 10-Q for the quarterly period ended June 30, 2009  File No. 001-31909
Dear Mr. O’Kane:

We have reviewed your filings and have the following comments. In our
comments, we ask you to provide us with  information to better understand your
disclosure. Where a comment requests you to  revise disclosure, the information you
provide should show us what the revised disc losure will look like and identify the annual
or quarterly filings, as app licable, in which you intend to first include it.  If you do not
believe that revised disclosure  is necessary, explain the reason in your response.  After
reviewing the information provided, we may raise additional comments and/or request
that you amend your filings.

 Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filings.  We look forward to working with you in these respects.  We
welcome any questions you may have about our comments or on any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Christopher O’Kane
Aspen Insurance Holdings Limited
December 23, 2009 Page 2

Form 10-K for the Fiscal Year Ended December 31, 2008

Item 7.  Management’s Discussion And Analys is Of Financial Condition And Results Of
Operations

Critical Accounting Policies
 Reserving approach, page 98, IBNR claims, pa ge 99, Actuarial range of gross reserves,
page 100 and Uncertainties, page 100
1. We believe your disclosure in the Cr itical Accounting Estimates section of
MD&A regarding the estimation of the reserve for loss and loss adjustment
expenses could be improved to better explain the judgments and uncertainties surrounding this estimate and the potential impact on your financial statements.
We believe in order to meet the principa l objectives of MD&A this disclosure
should enable the investor to understand 1) management’s method for establishing
the estimate; 2) whether and if so to wh at extent and why you have adjusted your
assumptions used to determine the estim ate from the assumptions used in the
immediately preceding period and 3) the pot ential variability in the most recent
estimate and the impact this variability may have on reported results, financial
condition and liquidity. Pleas e keep these points in mind in providing us your
responses to the comments listed below. Please revise your disclosure to include
the following information and also consider providing any additional information to achieve this objective.

a) Please describe the methods you used to determine your reserve for loss and loss adjustment expense. In your disclosure, include a description of
the method you use to calculate the IBNR  reserve for each material line of
business. For example, we understand that some companies may calculate this reserve by estimatin g the ultimate unpaid liability first and then
reducing that amount by cumulative paid  claims and by case reserves, but
there may be other methods as well. In  addition, to the extent your interim
procedures for determining the re serve for loss and loss adjustment
expense differs from the annual proc edures, describe the differences.
b) As it appears you utilize actuaries in estimating the liability for unpaid claims and claims adjustment and ma y make adjustments to the actuarial
estimates, provide the following information:

1) Describe the method used by ma nagement to determine the
adjustment and the extent to which you rely on objective versus subjective determinations. Such adjustments may include, but not
be limited to, an incremental provision, a reduction in the liability, or a reversal of a pr eviously recorded adjustment.

Christopher O’Kane
Aspen Insurance Holdings Limited
December 23, 2009 Page 3
2) When such adjustments or reve rsals are made, include MD&A
disclosure that iden tifies the amount of the adjustment or
reversal, the method you used to determine it, and the specific
underlying reasons that explain why you believe the adjustment
or reversal is necessary.
2. In order to show investors th e potential variability in the most recent estimate of
your loss reserve, quantify and present pref erably in a tabular format the impact
that reasonably likely cha nges in the key assumptions identified may have on
reported results, financial position and liqui dity by each line of business. Explain
why management believes the scenarios quantified are reas onably likely.
 Total cash and investments, page 116

3. Please revise your disclosures, here a nd throughout the filing, to include a
discussion of the amounts of securities in your investment portfolio that are
guaranteed by third parties along with th e credit rating with and without the
guarantee. Also disclose any significant concentration in  a guarantor, both direct
exposure (i.e. investments in a guarantor) and indirect exposure (i.e. investments
guaranteed by a guarantor). Please avoid re ferences to weighted average ratings.
 Valuation of investments, page 117

4. You state in Note 2c to y our financial statements that  you use a third party pricing
service to price a significant portion of your securities. Please revise your
disclosure to clarify the following:
a) Whether you adjusted the quotes and pr ices obtained from the brokers and
pricing services during th e periods presented;
b) Indicate the number of quotes or  prices you generally obtained per
instrument, and if you obtained mu ltiple quotes or prices, how you
determined the ultimate value used in your financial statements;
c) The extent to which third parties are gathering observable market
information as opposed to using unobservable inputs and/or proprietary models in making valuation judgments and determinations;
d) Whether the broker quotes are bi nding or non-binding; and
e) The procedures you performed to validate the prices you obtained to ensure the fair value determinati on is consistent with SFAS 157, Fair
Value Measurements, and to ensure that you properly classified your assets and liabilities in the fair value hierarchy.

Christopher O’Kane
Aspen Insurance Holdings Limited
December 23, 2009 Page 4  Item 8.  Financial Statements and Supplementary Data

 Notes to Consolidated Financial Statements

 11.  Income Taxes, page F-34

5. Your income tax reconciliation on page F-35 indicates that the prior period
adjustment represents approximately 24%  of your tax provision for 2007.  Please
revise your disclosure here or in MD&A  to explain why you recorded such a
significant income tax benefit re lated to prior periods in 2007.
 Item 11.  Executive Compensation

Compensation Discussion and Analysis, page 139
6. The Compensation Discussion and Analys is does not disclose the business
performance plans used to determine cha nges in base salaries.  In addition, the
Compensation Discussion and Analysis does not disclose object ives established
at the NEO’s annual performance review used to assess each individual’s
contribution.  Please provide us with draft disclosure for your Form 10-K for
your fiscal year ending December 31, 2009, which describes the business performance plans and any other goals or  objectives used to determine changes
in your NEO’s base salaries and annual cash bonuses.  Please also confirm that
in your Form 10-K for your fiscal year ending December 31, 2009 you will
discuss the achievement of the goals and how the level of achievement will
affect base salaries and the actual bonuses  to be paid.  To the extent that the
objectives are quantified, the disc ussion should also be quantified.
 Form 10-Q for the Quarterly Period Ended June 30, 2009

Item 6.  Exhibits, page 71

7. We note that the Letter of Credit Facility between Aspen Insurance Limited and
Citibank Europe Plc, dated April 29, 2009, which was filed as an exhibit to the
Form 8-K filed on May 4, 2009, was not listed in the exhi bit index for the
Form 10-Q for the quarter ended June 30, 2009.  Please confirm that such exhibit
will be listed in the exhibit index for your  next report on Form 10-K for the fiscal
year ended December 31, 2009.  Also, please acknowledge that future material agreements executed or becoming effectiv e during the reporting period reflected
by a Form 10-Q or Form 10-K will be listed in the exhibit index for that report.

   *    *    *

Christopher O’Kane
Aspen Insurance Holdings Limited December 23, 2009 Page 5
 Please respond to these comments within  10 business days or tell us when you
will provide us with a response.  Please furnish a letter that keys your responses to our comments and provide the requested information.  Detailed letters gr eatly facilitate our
review.  Please furnish the letter to us via EDGAR under the form type label CORRESP.

 We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filings to be certain that the filings include all information required under the Securities Exchange Act of 1934 and that they have provided all information
investors require for an informed invest ment decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.
  In connection with responding to our co mments, please provide, in your letter, a
statement from the company acknowledging that:
• the company is responsible for the adequacy  and accuracy of the disclosure in the
filings;
• staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filings; and
• the company may not assert staff comme nts as a defense in any proceeding
initiated by the Commission or any person under the federal secu rities laws of the
United States.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filings or in response to our comments on your filings.
 Please contact James Peklenk, Staff A ccountant, at (202) 551-3661 or Mark
Brunhofer, Senior Staff Acc ountant, at (202) 551-3638 if you have any questions
regarding the processing of your response as well as any questions regarding comments
on the financial statements and related ma tters.  You may cont act Sebastian Gomez
Abero, Staff Attorney, at (202) 551-3578 with questions on any of the other comments.
In this regard, do not hesitate to contact me, at (202) 551-3679.

Sincerely,    Jim B. Rosenberg Senior Assistant Chief Accountant