The work, although not free from errors, is a conscientious effort to clear up the family history of the Borgias.
At the close of 1872 I likewise entered into the discussion by publishing a note on the history of the Borgias.

This followed the appearance of the volume of the _Geschichte der Stadt Rom im Mittelalter_, which embraced the epoch of Alexander VI.

My researches in the archives of Italy had placed me in possession of a large amount of original information concerning the Borgias, and as it was impossible for me to avail myself of this mass of valuable details in that work, I decided to use it for a monograph to be devoted either to Caesar Borgia or to his sister, as protagonist.
I decided on Madonna Lucretia for various reasons, among which was the following: in the spring of 1872 I found in the archives of the notary of the Capitol in Rome the protocol-book of Camillo Beneimbene, who for years was the trusted legal adviser of Alexander VI.

This great manuscript proved to be an unexpected treasure; it furnished me with a long series of authentic and hitherto unknown documents.

It contained all the marriage contracts of Donna Lucretia as well as numerous other legal records relating to the most intimate affairs of the Borgias.