In Assassin's Creed: Brotherhood, Rome is the main setting for Ezio Auditore's campaign.
The game continues Ezio's story after Assassin's Creed II and places him in Renaissance Rome, where the Borgia family controls much of the city's political and military power. Ezio works to weaken Borgia influence, rebuild the Assassin Brotherhood, and recover control of districts across the city.
Rome's large open-world design was a major feature of Brotherhood. Ezio can recruit and train new Assassins, destroy Borgia towers, restore shops and landmarks, and use restored infrastructure to move through the city. The campaign also includes missions involving Leonardo da Vinci and the Papal forces.
Florence is Ezio's birthplace and an important location in Assassin's Creed II, but it is not Brotherhood's primary city. Constantinople becomes the main setting for Assassin's Creed Revelations, while Jerusalem is central to Altaïr's campaign in the original game. Brotherhood was released in 2010 and expanded the series' social and recruitment systems.