When, by the decree of 27 September 1807 signed at Fontainebleau, Napoleon I bought his brother-in-law Camille Borghèse’s collection, he gave his museum the largest collection of Roman antiquities in the early 19th century. This acquisition came to us after traveling through some stormy periods of history. While it is renowned for its princely origins and a few exceptional masterpieces, there is a lack of knowledge on the details of the works it comprises. In addition to giving the exact composition of the collection acquired by the Emperor, the catalogue makes use of the available archives (fully reproduced in the catalogue) to provide an accurate and documented response to the questions that have gone unanswered: how many objects were acquired? What types of object? Can all the acquired objects be found in the collections today?