In Assassin's Creed Revelations, Ezio searches for Altaïr's secrets in Constantinople.
The game takes Ezio to the Ottoman capital in the early sixteenth century. He seeks five Masyaf Keys, which eventually allow him to access the sealed library associated with Altaïr Ibn-La'Ahad. Constantinople provides the main setting for this search and for Ezio's interactions with the local Assassin guild.
The city is portrayed during the reign of Sultan Bayezid II and the succession struggle involving his sons Selim and Ahmet. Ezio also meets Sofia Sartor, a bookseller who helps him locate the keys. The narrative combines Ottoman political events with the series' fictional precursor technology and secret societies.
Constantinople is the historical name used in the game and was also known as Istanbul in later usage. The setting should not be confused with Masyaf, the Syrian fortress where Altaïr's library is located, or with the earlier game's cities of Jerusalem and Damascus.