Which Roman leader is the principal antagonist of Assassin's Creed Brotherhood?

Cesare Borgia is the principal antagonist of Assassin's Creed Brotherhood. He commands Templar forces in Italy and seeks power through military conquest and political control.

The game follows Ezio Auditore after the events of Assassin's Creed II. Much of the story takes place in Rome, where Cesare and his allies dominate the city. Ezio works to rebuild the local Assassin Brotherhood and weaken the Borgia regime.

Cesare was a real historical figure, the son of Pope Alexander VI and the brother of Lucrezia Borgia. Assassin's Creed Brotherhood uses historical figures and events as part of its fictional conflict between Assassins and Templars.

Rodrigo Borgia, Cesare's father, was the major antagonist of Assassin's Creed II and appears in Brotherhood as well. The distinction matters because Cesare becomes the central military threat in the later game.