In Assassin's Creed Brotherhood, Ezio Auditore primarily seeks to liberate Rome.
Released in 2010, Brotherhood continues Ezio's story after Assassin's Creed II. The game is set chiefly in Renaissance Rome, where the Borgia family controls much of the city through military power, money, and political influence. Ezio works to weaken that control by eliminating key figures, restoring districts, and recruiting fellow Assassins.
Rome is unusually important in the series because it functions as one large connected open-world setting rather than simply one stop among several cities. The player can repair shops, tunnels, aqueducts, and landmarks, gradually changing the city's economy and movement options. The Colosseum and the Vatican area are among its notable locations.
Venice and Florence are strongly associated with Ezio because they feature prominently in Assassin's Creed II. Constantinople is the principal setting of Assassin's Creed Revelations. Brotherhood's defining city, however, is Rome, and its liberation structure is central to the game's progression.