The Equestrian Order of the Holy Sepulchre of Jerusalem, also called Order of the Holy Sepulchre or Knights of the Holy Sepulchre, is a Roman Catholic order of knighthood under the protection of the Holy See. The Pope is sovereign of the Order. Founded as Milites Sancti Sepulcri attached to the Augustinian Canons Regular of the Holy Sepulchre in Jerusalem, recognised in 1113 by Papal bull of Pope Paschal II and of Pope Calistus II in 1122. It traces its roots to circa 1099 under the Frankish Duke Godfrey of Bouillon, Advocatus Sancti Sepulchri, "Defender of the Holy Sepulchre", one of the leaders of the First Crusade and first ruler of the Kingdom of Jerusalem. It is an internationally recognised order of knighthood.