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                                                                    EXHIBIT 99.1


Contact:  For Markel Corporation:                 For Gryphon Holdings Inc.:
          Steven Markel                           Stephen A. Crane
          Markel Corporation                      Gryphon Holdings Inc.
          (804) 965-1675                          (212) 825-1200

          Fred Spar/Josh Rosen
          Kekst and Company
          (212) 521-4800


                                                           FOR IMMEDIATE RELEASE

                MARKEL AND GRYPHON ANNOUNCE DEFINITIVE AGREEMENT

RICHMOND, Va., and NEW YORK, NY., November 25, 1998 -- Markel Corporation (NYSE:
MKL) and Gryphon Holdings Inc. (Nasdaq: GRYP) announced today that they have
signed a definitive agreement providing for the acquisition of Gryphon by
Markel.

Under terms of the agreement, which has been approved unanimously by the Boards
of Directors of both companies, Markel will continue its $19.00 per share
all-cash tender offer for all Gryphon common stock and will acquire any
remaining shares in a follow on merger. The transaction, including the
assumption or retirement of preferred shares and debt, is valued at
approximately $200 million.

The transaction is subject to required regulatory approvals and is expected to
be completed in January of 1999.

Markel Corporation Vice Chairman, Steven Markel said, "This transaction is a win
for the shareholders, policyholders, and employees of both companies. Markel and
Gryphon have complementary lines of business and we have high regard for
Gryphon's underwriting capabilities. We are confident that our size and
financial strength will enhance Gryphon's ability to attract and retain
business. In turn, we anticipate Gryphon will expand our product offerings in
the excess and surplus lines of business and make a significant contribution to
our future financial and competitive strength."

Gryphon's President & CEO, Stephen A. Crane, said, "We are pleased to be
partners with Markel Corporation, a first-class specialty insurance company. The
merger will further our long-term strategic objectives of providing value to our
shareholders, premium service to our insureds, and meaningful careers to our
employees."
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Markel Corporation markets and underwrites specialty insurance products and
programs to a variety of niche markets. In each of these markets, the Company
seeks to provide quality products and excellent customer service so that it can
be a market leader. The financial goals of the Company are to earn consistent
underwriting profits and superior investment returns to build shareholder value.

Gryphon Holdings operates through its main subsidiary, Gryphon Insurance Group,
as a specialty property and casualty underwriting organization. The Company's
wholly-owned insurance subsidiaries are Associated International Insurance
Company, Calvert Insurance Company, and the First Reinsurance Company of
Hartford.

Markel's tender offer for common shares of Gryphon expires at 6:00 p.m., New
York City time, on December 4, 1998, unless extended. Markel expects to announce
an extension of the tender offer early next week. Any extension of the offer
will be followed as promptly as practicable by public announcement thereof, with
such announcement to be made no later than 9:00 a.m., New York City time, on the
next business day after the previously scheduled expiration date.

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