In Assassin's Creed Brotherhood, Cesare Borgia is the main historical Templar antagonist.
Cesare Borgia commands the Borgia forces that control Rome during the game's early sixteenth-century story. He is the son of Rodrigo Borgia, who appeared as the principal antagonist in Assassin's Creed II. Brotherhood follows Ezio Auditore's campaign to dismantle Cesare's power and rebuild the Assassin Brotherhood in Rome.
The game dramatizes Cesare's political and military ambitions alongside real historical names and events, but it is not a literal biography. Rodrigo Borgia appears in the story as Pope Alexander VI and as Cesare's father. Confusing the two is common because both are members of the Borgia family and both hold central roles in the series' fictionalized account of Renaissance Italy.