The original Assassin's Creed is set primarily in 1191, during the Third Crusade. Altaïr Ibn-La'Ahad's missions take him among cities including Masyaf, Jerusalem, Acre, and Damascus while he hunts targets connected to the Templars.
The date places the game after the Crusaders' defeat at the Battle of Hattin in 1187 and during the campaign associated with Richard the Lionheart. The game uses real medieval locations and historical figures, but its secret Assassin–Templar conflict is fictionalized.
Players sometimes confuse 1191 with 1189–1192, the broader period commonly associated with the Third Crusade. The game focuses on one year within that wider campaign. Later entries move to different periods, so the date is specific to the first game's main historical storyline.