The original Assassin's Creed takes place in 1191. The historical campaign is set during the Third Crusade, when Altaïr Ibn-La'Ahad operates as an Assassin in the Holy Land.
The game visits several major cities, including Jerusalem, Acre, and Damascus. These locations are presented as large districts connected by the wider Kingdom, giving the player a stylized version of the medieval Levant rather than a completely literal reconstruction.
1191 places the story during the reign of Richard I of England, commonly known as Richard the Lionheart. The game uses real Crusades-era figures alongside fictional characters and its science-fiction framing device involving Desmond Miles.
The date is sometimes confused with 1099, the year of the First Crusade's capture of Jerusalem. Assassin's Creed instead uses the later Third Crusade period, almost a century afterward. Its historical setting therefore predates Ezio Auditore's Renaissance adventures by more than 300 years.