Pope military aid from Pope Urban II in the ongoing Byzantine–Seljuq wars. Urban, at the council of Clermont, called the First Crusade to assist the Byzantine Empire to regain the old Christian territories, especially Jerusalem. With the East–West Schism, the Eastern Orthodox Church and the Catholic Church split definitively in 1054. This fracture was caused more by political events than by slight divergences of creed. Popes had galled the Byzantine emperors by siding with the king of the Franks, crowning a rival Roman emperor, appropriating the Exarchate of Ravenna, and driving into Greek Italy. In the Middle Ages, popes struggled with
Pope Urban II repeatedly lifted and reimposed as the king promised to forswear her and then repeatedly returned to her. A public penance in 1104 ended the controversy, although Bertrade remained active in attempting to see her sons succeed Philip instead of Louis.) The Pope's movement took its first public shape at the Council of Piacenza, where, in March 1095, Urban II received an ambassador from the Byzantine Emperor Alexios I Komnenos asking for help against the Muslim Seljuk Turks who had taken over most of formerly Byzantine Anatolia. A great council met, attended by numerous Italian, Burgundian, and French bishops in such