Rome is the city Ezio defends while leading the Assassin Brotherhood in Assassin's Creed Brotherhood.
Brotherhood continues Ezio's story after Assassin's Creed II and places most of its action in Renaissance Rome. Ezio works to weaken the Borgia family, free the city from their influence, and rebuild the local Assassin network. The city functions as both the main open-world map and the center of the game's political conflict.
The Borgia power structure is led by Rodrigo Borgia, who appears as Pope Alexander VI, and his son Cesare Borgia. Historical characters and locations are woven into a fictional struggle between Assassins and Templars.
Players may associate Ezio with Florence and Venice because those cities are major settings in Assassin's Creed II. Constantinople is instead the principal setting of Assassin's Creed Revelations. Brotherhood's defining urban setting is Rome, including the Vatican and surrounding districts.