EXHIBIT 5.1






                                  May 24, 2001



Markel Corporation
4521 Highwoods Parkway
Glen Allen, Virginia 23060

Gentlemen:

          As counsel to Markel Corporation (the "Company"), we are providing
this opinion in connection with your preparation of the Registration Statement
on Form S-8 (the "Registration Statement") to be filed with the Securities and
Exchange Commission with respect to 100,000 shares of the Company's Common
Stock, no par value, and an indeterminate amount of participation interests to
be offered pursuant to the Markel Corporation Retirement Savings Plan (the
"Plan").

          We are of the opinion that the 100,000 shares of Company Common Stock
to be offered pursuant to the Plan have been validly authorized and, when issued
or sold in accordance with the terms of the Plan, will be legally issued, fully
paid and nonassessable.

          We hereby consent to the filing of this opinion with the Securities
and Exchange Commission as an exhibit to the Registration Statement.



                                             Very truly yours,


                                             /s/ McGuireWoods LLP