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
Clermont-Ferrand Jerusalem from Muslim domination: Pope Urban II preached the crusade there in 1095, at the Second Council of Clermont. In 1120, following repeated crises between the counts of Auvergne and the bishops of Clermont and in order to counteract the clergy’s power, the counts founded the rival city of Montferrand on a mound next to the fortifications of Clermont, on the model of the new cities of the Midi springing up in the 12th and 13th centuries. Until the early modern period, the two remained separate cities: Clermont, an episcopal city; Montferrand, a comital one. Clermont became a royal city