Before 1054, Roman Catholicism and the Eastern Orthodox churches were just mere branches of the One Apostolic Church. Yet even so, for a long span of time, division of these two factions of Christendom had been pervasive, which gradually increased. The rift had caused a widespread schism, which primarily traces its roots from their differences in culture, religion and politics. In that fateful year, 1054 AD, an official split had occured when Roman Catholicism’s leader, Pope Leo IX, had excommunicated Constantinople’s Patriarch, Michael Cerularious, who had condemned the pope to return the favor, which resulted to mutual excommunication. Because of this, the church had remained in division and are separate even up to present. Constantinople’s Patriarch, Michael Cerularius, had assumed office from 1043-1058 AD, which had spanned the time when Eastern Orthodoxy had seperated itself formally from Roman Catholicism. He had played a key role in propagating the circumstances which eventually led to the Great Schism between the two Churches. During the era of the Crusades in 1095 AD, Rome had allied themselves with Constantinople which would protect the Holy land from the Turks, which had provided a small spark, heralding the slim possibility of reuniting the two opposing factions. Yet, in the year 1204, which marked the Fourth Crusade’s end, which caused the Romans’ Sacking of the Constantinople city, that small ray had been extinguished as the hostility between the two factions had continued to become worse. Up to the present era, the Roman Catholics in the West and the Orthodox Church in the East had remained determinedly divided and autonomous, unwilling to reconcile. However, in the year 1965, The Patriarch Athenagoras and Pope Paul the Sixth had agreed to rescind their excommunication to each other from 1054 officially, which, in the hindsight, is but a first step for peace.