In which city is most of Assassin's Creed Revelations set?

Most of Assassin's Creed Revelations is set in Constantinople.

The game follows Ezio Auditore after the events of Assassin's Creed Brotherhood as he travels to the Ottoman capital in the early 16th century. Constantinople, now Istanbul, is divided in the game into districts that players explore while investigating Altaïr's legacy and the Templar presence.

The story also includes sections in Masyaf and memory sequences from the life of Altaïr Ibn-La'Ahad. Ezio's search for Altaïr's keys leads him into the history of the Assassin fortress and the wider political world of the Ottoman Empire.

The city was officially renamed Istanbul in the 20th century, but Constantinople is the historically appropriate name for the period depicted. Venice is associated particularly with Assassin's Creed II, while Alexandria is central to Assassin's Creed Origins.