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
Saint-Flour, Cantal a fortress in the ruins of the monastery, but, seized with remorse, donated it once more to Odilo of Cluny. Urban II, following the Council of Clermont (1095) consecrated the new abbey church, which received a triple dedication reflecting local tradition and present affiliations: Saint-Sauveur, Saint Pierre and Saint Flour. The diocese of Saint-Flour was established in August 1317 by the Avignon pope, John XXII. During the Revolution the commune took several successive names, de-Christianized as Fort-Cantal, "Fort-Libre" then Mont-Flour before retrieving its ancient historic designation in "an II" (1793). The territory of the commune was never changed. Briefly, between