Who is the main antagonist of Assassin's Creed: Brotherhood?

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

Cesare is the son of Rodrigo Borgia, who was the principal antagonist of Assassin's Creed II. In Brotherhood, Cesare commands military forces and seeks to expand Borgia control across Italy. His campaign brings the conflict directly to Rome, where Ezio Auditore works to rebuild the Assassin Brotherhood and oppose the Borgia family.

Rodrigo remains an important figure in the story, but Cesare is the central enemy Ezio confronts. This family relationship is a common source of confusion because both men are historical members of the Borgia dynasty and both appear in the series.

The historical Cesare Borgia lived from 1475 to 1507 and was a powerful Renaissance military leader. The game adapts real people and events for its fictional Assassin-Templar narrative, so its depiction is not a complete biography. Brotherhood uses Rome as its main city and expands the gameplay with recruitable Assassin allies.