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 V orders of the antipope Clement VII. The Western Schism caused the process to stop, but it was revived centuries later, and led to the beatification of Urban V on 10 March 1870 by Pope Pius IX. His feast day is celebrated on 19 December, the day of his death. This was decided upon by a General Chapter of the Benedictine Order held in 1414. Pope Urban V Pope Urban V (; 1310 – 19 December 1370), born Guillaume de Grimoard, was Pope from 28 September 1362 until his death in 1370 and was also a member of the Order of