Christian Church

===Great Schism of 1054===
Although there had long been frictions between the [[Bishop of Rome]] (i.e., the patriarch of the Catholic Church proper) and the eastern patriarchs within the [[Byzantine Empire]], Rome's [[Charlemagne#Imperial diplomacy|changing allegiance]] from Constantinople to the [[Frankish Empire|Frankish]] king Charlemagne set the Church on a course towards separation. The political and theological divisions would grow until [[East–West Schism|Rome and the East excommunicated each other in the 11th century]], ultimately leading to the division of the Church into the [[Catholic Church|Western]] (Catholic) and [[Eastern Orthodox Church|Eastern]] (Orthodox) churches.<ref name="CHRISTIANITY IN HISTORY" /> In 1448, not long before the Byzantine Empire collapsed, the Russian Orthodox Church gained independence from the [[Ecumenical Patriarchate|Patriarch of Constantinople]].{{citation needed|date=July 2023}}

As a result of the [[High Middle Ages|redevelopment of Western Europe]], and the [[Decline of the Byzantine Empire|gradual fall of the Eastern Roman Empire]] to the [[Arab]]s and [[Turkish people|Turks]] (helped by [[Fourth Crusade|warfare against Eastern Christians]]), the final [[Fall of Constantinople]] in 1453 resulted in Eastern scholars fleeing the Muslim hordes bringing ancient manuscripts to the West, which was a factor in the beginning of the period of the [[Renaissance|Western Renaissance]] there. [[Rome]] was seen by the Western Church as Christianity's heartland.<ref>Aristeides Papadakis, John Meyendorff, ''The Christian East and the Rise of the Papacy: The Church 1071-1453 A.D.'', St. Vladimir's Seminary Press, August 1994, {{ISBN|0-88141-057-8}}, {{ISBN|978-0-88141-057-0}}</ref> Some Eastern churches even broke with Eastern Orthodoxy and entered into communion with Rome ([[Eastern Catholic Churches|the ''"Uniate"'' Eastern Catholic Churches]]).