SCHEDULE 14A INFORMATION

                PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                               (AMENDMENT NO.___)

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[ ]     Preliminary Proxy Statement
[ ]     Definitive Proxy Statement
[ ]     Confidential,  for Use of the  Commission  Only  (as  permitted  by Rule
        14a-6(e)(2))
[X]     Definitive Additional Materials
[ ]     Soliciting Material Pursuant to sec. 240.14a-11(c) or sec. 240.14a-12

                       21ST CENTURY INSURANCE CORPORATION

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                (NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)





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    (NAME OF PERSON(S) FILING PROXY STATEMENT, IF OTHER THAN THE REGISTRANT)

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      SUPPLEMENT TO PROXY STATEMENT FOR 2003 ANNUAL MEETING OF STOCKHOLDERS
                           TO BE HELD ON JUNE 25, 2003

May 30, 2003

Re:   Correction to Biographical Information of Gregory M. Shepard (Director and
      Director Nominee)

Dear Shareholder:

In  connection  with the 2003 Annual  Meeting of  Shareholders  of 21st  Century
Insurance Group (the "Company") to be held on June 25, 2003, you recently should
have received  copies of the Notice of Annual  Meeting of  Shareholders  and our
Proxy Statement (the "Proxy Statement").

In light of information that came to the Company's  attention  subsequent to the
mailing of the Proxy  Statement,  the Company is amending the Proxy Statement to
supplement the  biographical  information of Gregory M. Shepard,  a director and
director  nominee,  to include  information  about the consent decree  described
below.

The  biographical  information  of  Gregory  M.  Shepard  set forth in the Proxy
Statement under the caption  "Nominees For Board of Directors" is hereby amended
and restated as follows:

GREGORY M. SHEPARD             Director since 1995                        Age 47

Chairman of the Board and President of American Union  Insurance  Company (AUIC)
since  1985.  Previously,  Mr.  Shepard  also served as Chairman of the Board of
Directors and President of Direct Auto Insurance Company, which changed its name
to AUIC in 1998, and American Union Financial  Corporation,  American Union Life
Insurance Company, and Direct Auto Indemnity Company,  which merged into AUIC in
1998 and 1999. In addition, he was Chairman and President of Illinois HealthCare
Insurance  Company until 2000. In September  2000, Mr. Shepard  consented to the
entry of a cease and desist order by the Securities and Exchange Commission,  in
connection  with his purchase of certain  shares of stock of Meridian  Insurance
Group, Inc. through American Union Financial  Corporation,  of which Mr. Shepard
was then President and 50% owner,  while that company's  tender offer for shares
of Meridian  Insurance Group was  outstanding.  Pursuant to the cease and desist
order,  Mr.  Shepard was ordered to cease and desist from  committing or causing
any violation and any future violation of Rule 14e-5 of the Securities  Exchange
Act.  Mr.  Shepard  consented  to the entry of the order  without  admitting  or
denying the findings set forth in the order.

You may vote or change your vote as described on page 1 of the Proxy  Statement.
If you have any questions or need to obtain a new proxy card,  please contact us
at the (800)  443-3100,  Ext.  2962.  If you intend to request  and submit a new
proxy  card,  please  do so as soon as  possible  to  ensure  that  your vote is
received in time to be counted at the Annual Meeting.

Sincerely,

/s/ Michael J. Cassanego

Michael J. Cassanego
Secretary

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