SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 --------------

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. 8)

                      WHITE MOUNTAINS INSURANCE GROUP, LTD.
                                (NAME OF ISSUER)


                                  Common Shares
                         (TITLE OF CLASS OF SECURITIES)


                                   G9618E 10 7
                                 (CUSIP NUMBER)


         Check the following box if a fee is being paid with this statement |_|.
(A fee is not required only if the filing person: (1) has a previous statement
on file reporting beneficial ownership of more than five percent of the class of
securities described in Item 1; and (2) has filed no amendment subsequent
thereto reporting beneficial ownership of less than five percent of such class.)
(See Rule 13d-7.)

         * The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

         The information required in the remainder of this cover page shall not
be deemed to the "filed" for the purpose of Section 18 of the securities
Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that
section of the Act but shall be subject to all other provisions of the Act
(however, see the Notes).


                                Page 1 of 6 pages



CUSIP No. G9618E 10 7

------- -----------------------------------------------------------------------
1       NAME OF REPORTING PERSON
        S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
        JOHN J. BYRNE
        138-24-5813
------- -----------------------------------------------------------------------
2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP               (a)  |_|
                                                                       (b)  |_|
------- -----------------------------------------------------------------------
3       SEC USE ONLY
------- -----------------------------------------------------------------------
4       CITIZENSHIP OR PLACE OF ORGANIZATION
        UNITED STATES
---------------------------------- ----- --------------------------------------

                                   5     SOLE VOTING POWER
            NUMBER OF                    1,175,101**
             SHARES                ----- --------------------------------------
          BENEFICIALLY             6     SHARED VOTING POWER
            OWNED BY                     53,863**
              EACH                 ----- --------------------------------------
            REPORTING              7     SOLE DISPOSITIVE POWER
           PERSON WITH                   1,175,101**
                                   ----- --------------------------------------
                                   8     SHARED DISPOSITIVE POWER
                                         53,863**
---------------------------------- ----- --------------------------------------
9       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
        1,228,964**
------- -----------------------------------------------------------------------
10      CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                            |_|
------- -----------------------------------------------------------------------
11      PERCENT OF CLASS REPRESENTED
        BY AMOUNT IN ROW (9)
        14.9%**
------- -----------------------------------------------------------------------
12      TYPE OF REPORTING PERSON
        IN
------- -----------------------------------------------------------------------

** For additional information, see Schedule A hereto.


                               Page 2 of 6 pages



Item 1(a).        NAME OF ISSUER:

         White Mountains Insurance Group, Ltd.

Item 1(b).        ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

         28 Gates Street
         White River Junction, VT 05001

Item 2(a).        NAME OF PERSON FILING:

         John J. Byrne

Item 2(b).        ADDRESS OF PRINCIPAL BUSINESS OFFICE:

         28 Gates Street
         White River Junction, VT 05001

Item 2(c).        CITIZENSHIP:

         United States

Item 2(d).        TITLE OF CLASS OF SECURITIES:

         Common Shares

Item 2(e).        CUSIP NUMBER:

         G9618E 10 7

Item 3. IF THIS STATEMENT IS FILED PURSUANT TO RULES 13D-1(B), OR 13D-2(B),
CHECK WHETHER THE PERSON FILING IS A:

         Not applicable.

Item 4.  OWNERSHIP.

         (a)      AMOUNT BENEFICIALLY OWNED:

                  See Schedule A hereto.


                               Page 3 of 6 pages



         (b)      PERCENT OF CLASS:

                  See Schedule A hereto.

         (c)      NUMBER OF SHARES AS TO WHICH PERSON FILING THIS SCHEDULE 13G
                  HAS (I) SOLE POWER TO VOTE OR TO DIRECT THE VOTE; (II) SHARED
                  POWER TO VOTE OR TO DIRECT THE VOTE; (III) SOLE POWER TO
                  DISPOSE OR TO DIRECT THE DISPOSITION OF; OR (IV) SHARED POWER
                  TO DISPOSE OR TO DIRECT THE DISPOSITION of.

                  See Schedule A hereto.

Item 5.  OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

                  Not applicable.

Item 6.  OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

                  Not applicable.

Item 7.  IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
         SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.

                  Not applicable.

Item 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.

                  Not applicable.

Item 9.  NOTICE OF DISSOLUTION OF GROUP.

                  Not applicable.

Item 10. CERTIFICATION.

                  Not applicable.


                               Page 4 of 6 pages



                                    SIGNATURE

         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this Statement is true, complete and
correct.


Date:    January 29, 2002

                                        By: /s/ John J. Byrne
                                            Name: John J. Byrne


                               Page 5 of 6 pages



                                                                    SCHEDULE A

                      BENEFICIAL OWNERSHIP OF COMMON SHARES


         The 14.9% of the common shares of White Mountains Insurance Group, Ltd.
(the "Company") shown in the foregoing Schedule 13G as beneficially owned by
John J. Byrne ("Mr. Byrne") was calculated using 8,264,681 common shares of the
Company outstanding on December 31, 2001 as shown in the official records of the
Company.

         The 1,228,964 common shares of the Company shown in the foregoing
Schedule 13G as beneficially owned by Mr. Byrne represent (a) 1,175,101 shares
held directly by Mr. Byrne, which includes 25,000 restricted shares which have
been issued to Mr. Byrne but are not yet earned; (b) 50,363 shares held by a
trust and a foundation as to which Mr. Byrne and/or Mrs. Byrne have voting and
dispositive power; and (c) 3,500 shares held by Memorial Sloan-Kettering Cancer
Center ("MSK") pursuant to a letter agreement between MSK and Mr. and Mrs. Byrne
dated December 30, 1992, as to which Mrs. Byrne shares voting and dispositive
power.

*        Mr. Byrne disclaims beneficial ownership of the shares listed in (b)
         and (c) above.,


                               Page 6 of 6 pages