Which historical figure is the main antagonist of Assassin's Creed Brotherhood?

Cesare Borgia is the main antagonist of Assassin's Creed Brotherhood.

The game places Ezio Auditore in Rome, where Cesare commands a powerful Templar-backed regime and seeks to expand his control across Italy. Ezio works to dismantle Cesare's influence by weakening his military, political, and financial network.

Cesare was a real Renaissance-era military leader and the son of Rodrigo Borgia, who became Pope Alexander VI. Assassin's Creed Brotherhood fictionalizes events and adds the series' secret-society mythology, but it uses recognizable political figures and conflicts from late fifteenth- and early sixteenth-century Italy.

Rodrigo Borgia is an important antagonist in Assassin's Creed II, so the two characters are often confused. Brotherhood focuses more directly on Cesare's ambitions, while Rodrigo's role is comparatively less central.