What is the title of Assassin's Creed's 2010 game centered on Ezio's leadership in Rome?

The 2010 game centered on Ezio's leadership in Rome is Assassin's Creed: Brotherhood. It is the direct sequel to Assassin's Creed II and continues Ezio Auditore's story after his rise as an Assassin.

Brotherhood moves much of the action to Rome, where Ezio works to weaken the Borgia family and rebuild the Assassin Brotherhood. A major feature lets him recruit and train new Assassins, then call on them during missions. The game also introduced a competitive multiplayer mode to the main series.

The title is sometimes confused with Assassin's Creed: Revelations, released in 2011. Revelations follows an older Ezio in Constantinople and also concludes Altaïr's storyline. Brotherhood is not a numbered sequel in its title, but it is commonly treated as the second major chapter of the Ezio trilogy, between Assassin's Creed II and Revelations.