September 12th (1213) was a Thursday. It's the 254th day of the year (255th in leap years) in the Gregorian calendar. There are 111 days left to the end of the year.
Historical Events for 12th September, 1213
» Albigensian Crusade: Simon de Montfort, 5th Earl of Leicester, defeats Peter II of Aragon e.g Peter II of Aragon at the Battle of Muret.