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 Church" (to Bologna), "liberating Christianity [Lat. Christianitatis]" (to Vallombrosa), and "the Asian church" (to the Catalan counts). Coincidentally or not, Fulcher of Chartres's version of Urban's speech makes no explicit reference to Jerusalem. Rather it more generally refers to aiding the crusaders' Christian "brothers of the eastern shore," and to their loss of Asia Minor to the Turks. It is still disputed what Pope Urban's motives were as evidenced by the different speeches that were recorded, all of which differ from each other. Some historians believe that Urban wished for the reunification of the eastern and western churches, a rift