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
History of the papacy (1048–1257) held the possibility of a reunion between the eastern and western Churches after almost four decades of schism, thereby strengthening the western Church in general and the papacy in particular. On November 27, 1095, Urban II made one of the most influential speeches in the Middle Ages at the Council of Clermont combining the ideas of making a pilgrimage to the Holy Land with that of waging a holy war against infidels. The pope called for a “War of the Cross,” or Crusade, to retake the holy lands from the unbelievers. France, the pope said, was already overcrowded and the