Exhibit 24

                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that BRUCE R. BERKOWITZ does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ BRUCE R. BERKOWITZ



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that JOHN J. BYRNE does hereby make, constitute
and appoint Raymond Barrette and George J. Gillespie, III, and each of them, as
true and lawful attorney-in-fact and agent of the undersigned, with full power
of substitution, resubstitution and revocation, for and in the name, place and
stead of the undersigned, to execute and deliver the Annual Report on Form 10-K,
and any and all amendments thereto; such Form 10-K and each such amendment to be
in such form and to contain such terms and provisions as said attorney or
substitute shall deem necessary or desirable; giving and granting unto said
attorney, or to such person or persons as in any case may be appointed pursuant
to the power of substitution herein given, full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary or, in the
opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ JOHN J. BYRNE



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that HOWARD L. CLARK, JR. does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ HOWARD L. CLARK, JR.



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that ROBERT P. COCHRAN does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ ROBERT P. COCHRAN



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that STEVEN E. FASS does hereby make, constitute
and appoint Raymond Barrette and George J. Gillespie, III, and each of them, as
true and lawful attorney-in-fact and agent of the undersigned, with full power
of substitution, resubstitution and revocation, for and in the name, place and
stead of the undersigned, to execute and deliver the Annual Report on Form 10-K,
and any and all amendments thereto; such Form 10-K and each such amendment to be
in such form and to contain such terms and provisions as said attorney or
substitute shall deem necessary or desirable; giving and granting unto said
attorney, or to such person or persons as in any case may be appointed pursuant
to the power of substitution herein given, full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary or, in the
opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ STEVEN E. FASS



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that GEORGE J. GILLESPIE, III does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ GEORGE J. GILLESPIE, III



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that JOHN D. GILLESPIE does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ JOHN D. GILLESPIE



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that EDITH E. HOLIDAY does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ EDITH E. HOLIDAY



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that FRANK A. OLSON does hereby make, constitute
and appoint Raymond Barrette and George J. Gillespie, III, and each of them, as
true and lawful attorney-in-fact and agent of the undersigned, with full power
of substitution, resubstitution and revocation, for and in the name, place and
stead of the undersigned, to execute and deliver the Annual Report on Form 10-K,
and any and all amendments thereto; such Form 10-K and each such amendment to be
in such form and to contain such terms and provisions as said attorney or
substitute shall deem necessary or desirable; giving and granting unto said
attorney, or to such person or persons as in any case may be appointed pursuant
to the power of substitution herein given, full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary or, in the
opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ FRANK A. OLSON



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that LOWNDES A. SMITH does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ LOWNDES A. SMITH



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that JOSEPH S. STEINBERG does hereby make,
constitute and appoint Raymond Barrette and George J. Gillespie, III, and each
of them, as true and lawful attorney-in-fact and agent of the undersigned, with
full power of substitution, resubstitution and revocation, for and in the name,
place and stead of the undersigned, to execute and deliver the Annual Report on
Form 10-K, and any and all amendments thereto; such Form 10-K and each such
amendment to be in such form and to contain such terms and provisions as said
attorney or substitute shall deem necessary or desirable; giving and granting
unto said attorney, or to such person or persons as in any case may be appointed
pursuant to the power of substitution herein given, full power and authority to
do and perform any and every act and thing whatsoever requisite, necessary or,
in the opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ JOSEPH S. STEINBERG



                      WHITE MOUNTAINS INSURANCE GROUP, LTD.

                                POWER OF ATTORNEY

KNOW ALL MEN by these presents, that ARTHUR ZANKEL does hereby make, constitute
and appoint Raymond Barrette and George J. Gillespie, III, and each of them, as
true and lawful attorney-in-fact and agent of the undersigned, with full power
of substitution, resubstitution and revocation, for and in the name, place and
stead of the undersigned, to execute and deliver the Annual Report on Form 10-K,
and any and all amendments thereto; such Form 10-K and each such amendment to be
in such form and to contain such terms and provisions as said attorney or
substitute shall deem necessary or desirable; giving and granting unto said
attorney, or to such person or persons as in any case may be appointed pursuant
to the power of substitution herein given, full power and authority to do and
perform any and every act and thing whatsoever requisite, necessary or, in the
opinion of said attorney or substitute, able to be done in and about the
premises as fully and to all intents and purposes as the undersigned might or
could do if personally present, hereby ratifying and confirming all that said
attorney or such substitute shall lawfully do or cause to be done by virtue
hereof.

IN WITNESS WHEREOF, the undersigned has duly executed these presents this 24th
day of February 2005.


                                               /s/ ARTHUR ZANKEL