In Assassin's Creed: Revelations, Constantinople is the main setting for Ezio's search for Altaïr's memories.
Ezio travels to Constantinople, the capital of the Byzantine Empire, to find keys connected to Altaïr's former headquarters in Masyaf. The keys unlock a series of memory sequences showing important moments from Altaïr's later life. This structure links Ezio's story directly to the protagonist of the first Assassin's Creed game.
The city is divided into districts and includes areas such as Galata and the Imperial district. Ezio also becomes involved with local Assassins and meets Sofia Sartor, a bookseller whose research helps him locate the Masyaf keys. Ottoman prince Suleiman is another major historical figure in the narrative.
The city is historically called Constantinople during the game's 1511 setting; it was renamed Istanbul in common official usage later in the twentieth century. Jerusalem and Damascus are important cities in the original game, but they are not Revelations' principal setting.