In Assassin's Creed Brotherhood, who is Ezio's primary rival and the Borgia leader?

In Assassin's Creed Brotherhood, Cesare Borgia is Ezio's primary rival and the Borgia leader.

Cesare commands the Borgia forces that control Rome and serves as the chief antagonist of Ezio's campaign. Ezio works to weaken Cesare's influence by building an Assassin network, liberating districts, recruiting allies, and confronting the Borgia military presence.

Rodrigo Borgia, also known as Pope Alexander VI, is Cesare's father and an important character from Assassin's Creed II. Brotherhood shifts the main personal conflict toward Cesare, whose ambition and military power drive the story. Juan Borgia is another member of the family, but he is not the central rival.

The historical Cesare Borgia was a powerful Italian Renaissance nobleman and military commander. The game fictionalizes parts of his life and portrays him within its secret-history framework. Brotherhood was released in 2010 and is primarily set in Rome.