What was the name of the Assassin's Creed series' first game set mainly in Constantinople?

Assassin's Creed: Revelations was the first Assassin's Creed game set mainly in Constantinople.

Released in 2011, Revelations follows an older Ezio Auditore as he travels to Constantinople, the capital of the Byzantine Empire, in search of Altaïr's lost knowledge. The city is divided into districts and includes landmarks inspired by its medieval architecture.

The game brings together the stories of Ezio and Altaïr, while Desmond Miles remains part of the modern-day narrative. Constantinople provides the principal setting, although the campaign also includes the nearby city of Cappadocia and historical memories connected to Altaïr.

The city is called Istanbul in modern usage, but Constantinople is the historical name used for the game's setting. Assassin's Creed II includes Venice and Florence, and Brotherhood centers on Rome, making Revelations the key entry associated with medieval Constantinople.