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                                                                     Exhibit 8.1

                                                               November 13, 2000



The Chase Manhattan Corporation
270 Park Avenue
New York, New York 10017



                                 Re:  Agreement and Plan of Merger dated as of
                                 September 12, 2000, by and among The Chase
                                 Manhattan Corporation and J.P. Morgan & Co.
                                 Incorporated

Ladies and Gentlemen:

                  We have acted as counsel to The Chase Manhattan Corporation
("Chase"), a Delaware corporation, in connection with the proposed merger (the
"Merger") of J.P. Morgan & Co. Incorporated ("Morgan"), a Delaware corporation,
with and into Chase. The Merger will be consummated pursuant to the Agreement
and Plan of Merger dated as of September 12, 2000, between Chase and Morgan (the
"Merger Agreement"). For purposes of this opinion, capitalized terms used and
not otherwise defined herein shall have the meaning ascribed thereto in the
Merger Agreement. This opinion is being delivered in connection with Chase's
Registration Statement on Form S-4 relating to the proposed Merger pursuant to
the Merger Agreement (the "Registration Statement") to which this opinion
appears as an exhibit.

                  In acting as counsel to Chase in connection with the Merger,
we have, in preparing our opinion, as hereinafter set forth, participated in the
preparation of the Merger Agreement and the preparation and filing of the
Registration Statement.
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                  You have requested that we render the opinion set forth below.
In rendering such opinion, we have assumed with your consent that (i) the Merger
will be effected in accordance with the Merger Agreement, (ii) the statements
concerning the Merger set forth in the Merger Agreement and the Registration
Statement are true, complete and correct and will remain true, complete and
correct at all times up to and including the Effective Time, (iii) the
representations made by Chase and Morgan in their respective letters delivered
to us for purposes of this opinion (the "Representation Letters") are true,
complete and correct and will remain true, complete and correct at all times up
to and including the Effective Time, and (iv) any representations made in the
Representation Letters "to the best knowledge of" or similarly qualified are
true, correct and complete without such qualification. We have also assumed that
the parties have complied with and, if applicable, will continue to comply with,
the covenants contained in the Merger Agreement.

                  We have examined the documents referred to above and the
originals, or duplicates or certified or conformed copies, of such records,
documents, certificates or other instruments and made such other inquiries as in
our judgment are necessary or appropriate to enable us to render the opinion set
forth below. We have not, however, undertaken any independent investigation of
any factual matter set forth in any of the foregoing.

                  If the Merger is effected on a factual basis different from
that contemplated in the Merger Agreement and the Registration Statement the
opinion expressed herein may be inapplicable. Our opinion is based on the
Internal Revenue Code of 1986, as amended (the "Code"), Treasury Regulations,
administrative interpretations, and judicial precedents as of the date hereof.
If there is any subsequent change in the applicable law or regulations, or if
there are
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subsequently any new applicable administrative or judicial
interpretations of the law or regulations, the opinion expressed herein may
become inapplicable.

                  Based on and subject to the foregoing, we hereby confirm our
opinion set forth in the discussion contained in the Registration Statement
under the caption "THE MERGER -- Material United States Federal Income Tax
Consequences of the Merger."

                  We express our opinion herein only as to those matters
specifically set forth in the Registration Statement and no opinion should be
inferred as to the tax consequences of the Merger under any state, local or
foreign law, or with respect to other areas of United States federal taxation.
We are members of the Bar of the State of New York, and we do not express any
opinion herein concerning any law other than the federal law of the United
States.

                  We hereby consent to the filing of this opinion as Exhibit 8.1
to the Registration Statement and to the references to our firm name therein.

                                                     Very truly yours,

                                                 /S/ Simpson Thacher & Bartlett

                                                     SIMPSON THACHER & BARTLETT