Johann Burchard

Johann Burchard (1450-1506) was a close associate to the Borgia family, acting as Pope Alexander VI's master of ceremonies. His work consisted of arranging the parties and orgies of the Borgia family. After the liberation of Rome and the death of his master, the Assassin Ezio Auditore da Firenze told his sister Claudia to keep an eye on him, suspecting him to have something to do with the Borgia diehards. However, Claudia noted that it was not very likely, as he hated throwing the Borgia's parties.

Source

 * Assassin's Creed: Brotherhood novel