Which Assassin's Creed game is set mainly in Constantinople and stars Ezio Auditore?

Assassin's Creed: Revelations is set mainly in Constantinople and stars Ezio Auditore.

Released in 2011, Revelations follows an older Ezio as he travels to Constantinople in the early sixteenth century. He searches for keys connected to Altaïr's former stronghold in Masyaf while becoming involved in the city's conflict between Assassins and Templars.

The game features districts on both sides of the Golden Horn, including the areas later known as Istanbul's historic quarters. Ezio also encounters Suleiman, the Ottoman prince who would become Suleiman the Magnificent. The story alternates between Ezio's mission and memories of Altaïr Ibn-La'Ahad.

Although the game is commonly described as taking place in Istanbul, the historical name Constantinople is used for the city during the period depicted. Revelations concludes Ezio's main trilogy, following Assassin's Creed II and Brotherhood, and also provides a major connection between Ezio, Altaïr, and Desmond.