<PAGE>
Exhibit 5.1
[LETTERHEAD OF ORRICK, HERRINGTON & SUTCLIFFE LLP]
June 26, 2000
Capital One Bank
11011 West Broad Street
Glen Allen, Virginia 23060
Re: Capital One Master Trust
Capital One Bank (Seller and Servicer)
Registration Statement on Form S-3
---------------------------------------
Ladies and Gentlemen:
We have acted as counsel for Capital One Bank, a Virginia banking
corporation (the "Bank"), in connection with the Registration Statement on Form
S-3 (the "Registration Statement") filed with the Securities and Exchange
Commission under the Securities Act of 1933, as amended (the "Act"), for the
registration under the Act of Asset Backed Certificates (collectively, the
"Certificates") to be issued from time to time in series (each, a "Series"),
each such Series representing undivided interests in the Capital One Master
Trust (the "Trust"). Each Series of Certificates will be issued pursuant to the
Pooling and Servicing Agreement (as amended, the "Pooling and Servicing
Agreement"), between the Bank, as Seller and Servicer by assignment from the
previous seller and servicer, and The Bank of New York, as Trustee.
We have examined such instruments, documents and records as we deemed
relevant and necessary as a basis of our opinion hereinafter expressed. In such
examination, we have assumed the following: (a) the authenticity of original
documents and the genuineness of all signatures; (b) the conformity to the
originals of all documents submitted to us as copies; and (c) the truth,
accuracy and completeness of the information, representations and warranties
contained in the records, documents, instruments and certificates we have
reviewed.
Based on such examination, we are of the opinion that when the
issuance of each Series of Certificates has been duly authorized by the
appropriate corporate action and the Certificates of such Series have been duly
executed, authenticated and delivered in accordance with the Pooling and
Servicing Agreement, and sold in the manner described in the Registration
Statement, any amendment thereto and the prospectus and prospectus supplement
relating thereto, the Certificates will be legally issued, fully paid, non-
assessable and binding obligations of the Trust and the holders of the
Certificates of such Series will be entitled to the benefits of such Pooling and
Servicing Agreement, except as enforcement thereof may be limited by applicable
bankruptcy, insolvency, reorganization, arrangement, fraudulent conveyance,
<PAGE>
Capital One Bank
June 26, 2000
Page 2
moratorium, or other laws relating to or affecting the rights of creditors
generally and general principles of equity, including without limitation
concepts of materiality, reasonableness, good faith and fair dealing, and the
possible unavailability of specific performance or injunctive relief, regardless
of whether such enforceability is considered in a proceeding in equity or at
law.
We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of our name wherever appearing in the
Registration Statement and the prospectus contained therein. In giving such
consent, we do not admit that we are "experts," within the meaning of the term
as used in the Act or the rules and regulations of the Securities and Exchange
Commission issued thereunder, with respect to any part of the Registration
Statement, including this opinion as an exhibit or otherwise.
Very truly yours,
/s/ Orrick, Herrington & Sutcliffe LLP
ORRICK, HERRINGTON & SUTCLIFFE LLP