Exhibit 5.1

                                 August 12, 1999

ACE Limited
The ACE Building
30 Woodbourne Avenue
Hamilton, HM 08, Bermuda

     Re:  ACE Limited
          Registration Statement on Form S-3
          ----------------------------------

Dear Sirs:

     We have acted as Cayman Islands counsel to ACE Limited (the "Company") in
connection with the registration of Ordinary Shares, Preferred Shares, Debt
Securities, Warrants to Purchase Ordinary Shares (the "Ordinary Share
Warrants"), Warrants to Purchase Preferred Shares (the "Preferred Share
Warrants"), Warrants to Purchase Debt Securities (the "Debt Warrants"; the
Ordinary Share Warrants, Preferred Share Warrants and Debt Warrants are
collectively referred to as the "Warrants") and Stock Purchase Contracts of the
Company under the Securities Act of 1933, as amended, in accordance with the
Company's Registration Statement on Form S-3 filed with the Securities and
Exchange Commission on May 20, 1999, as amended by Pre-Effective Amendment No. 1
to the Registration Statement filed with the Securities and Exchange Commission
on August 6, 1999, as amended by Pre-Effective Amendment No. 2 filed with the
Securities and Exchange Commission on August 12, 1999 (collectively, the
"Registration Statement").

     In rendering the opinions expressed herein, we have examined and are
familiar with the Registration Statement as an exhibit to which this opinion
will be filed.  We have also examined such other documents and instruments
(including the Company's Memorandum and Articles of Association, as amended) and
have made such further investigation as we have deemed necessary or appropriate
in connection with this opinion.

     We have relied in giving this opinion on certifications, given by the
Company's officers.  We have assumed that there will be no intervening changes
to the structure of the proposed issue, nor to the Company's Memorandum or
Articles of Association, the laws of the Cayman Islands or any other relevant
matter.

     Based upon and subject to the foregoing, and having regard for legal
considerations which we deem relevant, we are of the opinion that:

     (i)   On the basis that the contractual consideration (being worth not less
           than the par value) for the Ordinary Shares (including the Ordinary
           Shares issuable upon the exercise of the Ordinary Share Warrants) is
           duly transferred to, and received by, the Company, such Ordinary
           Shares issued or to be issued may properly be registered in the
           Company's share register and credited as fully paid under Cayman
           Islands law.

     (ii)  On the basis that the contractual consideration (being worth not less
           than the par value) for the Preferred Shares (including the Preferred
           Shares issuable upon the exercise of the Preferred Share Warrants),
           when the terms of such Preferred Shares are set, is duly transferred
           to, and received by, the Company, such Preferred Shares issued or to
           be issued may properly be registered in the Company's share register
           and credited as fully paid under Cayman Islands law.

     (iii) Fully paid shares are not subject to further calls or assessments by
           the Company.

     (iv)  The Company has been incorporated as an exempted company under the
           Companies Law (1995 Revision) of the Cayman Islands and the liability
           of its shareholders is limited to the amount, if any, unpaid on their
           shares (per Clause 5 of the Company's Memorandum of Association).  On


            the basis that all such shares are fully paid, there is no rule of
            Cayman Islands law that would impose any further liability on
            persons holding shares in the Company, merely by reason of such
            shareholding.

     (v)    The ACE INA Senior Indenture is duly authorized by ACE.

     (vi)   The ACE INA Subordinated Indenture is duly authorized by ACE.

     (vii)  The Guaranty is duly authorized by ACE.

     (viii) The ACE Senior Indenture is duly authorized by ACE.

     (ix)   The ACE Senior Notes are duly authorized by ACE.

     (x)    The ACE Subordinated Indenture is duly authorized by ACE.

     (xi)   The ACE Subordinated Notes are duly authorized by ACE.

     (xii)  The Warrant Agreements are duly authorized by ACE.

     (xiii) The Warrants, when the terms of such are set by the Pricing
            Committee of ACE, will be duly authorized by ACE.

     (xiv)  The Stock Purchase Contracts are duly authorized by ACE.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to all references to this firm in such Registration
Statement.

                                Yours faithfully,



                                Maples and Calder