The original Assassin's Creed begins in 1191, during the Third Crusade.
The game follows Altaïr Ibn-La'Ahad as he travels among the Levantine cities of Masyaf, Jerusalem, Acre, and Damascus. Its story combines fictional Assassin and Templar factions with the real political and military tensions of the late twelfth century.
The year 1191 places the narrative after the 1187 Battle of Hattin, when Saladin defeated the Crusader army and retook Jerusalem. Richard the Lionheart then led the Third Crusade, which forms the historical backdrop for the game's events. The game dramatizes history rather than presenting a documentary reconstruction.
Players sometimes confuse the setting with 1099, the year of the First Crusade's capture of Jerusalem, or with 1187, the year of Hattin. Neither is the game's principal starting year. Assassin's Creed II later moved the series forward several centuries to Renaissance Italy.