Which historical conflict forms the main setting of the first Assassin's Creed game?

The Third Crusade forms the main historical setting of the first Assassin's Creed game.

The story is set in 1191, during the conflict between forces associated with the Christian and Muslim worlds. Altaïr Ibn-La'Ahad carries out missions in the cities of Masyaf, Jerusalem, Acre, and Damascus while pursuing targets tied to the Templars.

The game uses real historical figures, including Richard the Lionheart, Robert de Sablé, and Saladin, alongside its fictional Assassin-Templar conspiracy. This blend of documented history and fictional mythology became a defining feature of the franchise.

The setting should not be confused with later games. Assassin's Creed Unity takes place during the French Revolution, while Assassin's Creed Odyssey is set during the Peloponnesian War.