In November, 1872, I delivered a lecture on the subject before the class in history at the Royal Bavarian Academy of Sciences in Munich, which was published in the account of the proceedings.

These records cast new light on the history of the Borgias, whose genealogy had only just been published by Cittadella.
There were other reasons which induced me to write a book on Donna Lucretia.

I had treated the political history of Alexander VI and Caesar at length, and had elucidated some of its obscure phases, but to Lucretia Borgia I had devoted no special attention.

Her personality appeared to me to be something full of mystery, made up of contradictions which remained to be deciphered, and I was fascinated by it.
I began my task without any preconceived intention.

I purposed to write, not an apology, but a history of Lucretia, broadly sketched, the materials for which, in so far as the most important period of her life, her residence in Rome, was concerned, were already in my possession.