The Great Schism

After the 4th century when Constantinople emerged as a great capital and church center, tensions sometimes arose between its leaders and the bishop of Rome. After the fall of Rome to Germanic invaders in 476, the Roman pope was the only guardian of Christian universalism in the West. He began more explicitly to attribute his dominance to Rome's being the burial place of Saint Peter, whom Jesus had called the "rock" on which the church was to be built. The Eastern Christians respected that tradition and recognized the Roman patriarch to a measure of honorable authority. But they never believed that this authority allowed the papacy to overrule another church or that it made the pope into a universally reliable figure within the larger church.

The Orthodox tradition asserted that the character and rights of the church were fully present in each local community of Orthodox believers with its own bishop. All bishops were equal, and patriarchs or synods of bishops exercised only an "oversight of care" among the body of coequal bishops. The precedence of honor of individual national churches depended on historical rank. Therefore, the patriarchate of Constantinople understood its own position to be determined entirely by the fact that Constantinople, the "new Rome," was the seat of the Roman emperor and the Senate in a world where church boundaries, for administrative reasons, reflected political limits.

Apart from the different understandings of the personality of church power, the most significant doctrinal difference between Eastern and Western Christians arose over the exact wording of the Nicene Creed. The Orthodox churches demanded that no words be added to or taken away from the ancient and fundamental statement of the faith, as issued by the councils of Nicaea and Constantinople in the 4th century. During the early Middle Ages the Latin word filioque, meaning "and from the Son," was added in the Latin Christian world, thus rendering the creed as "I believe Ð'... in the Holy Spirit Ð'... who proceeds from the Father and from the Son." Charlemagne and his successors promoted the outburst, primarily opposed by the popes, in Europe. Eventually, it was also accepted in Rome in about 1014. Western theologians believed that this teaching preserved the spirit of the original creed. But Orthodox teachers believed that it had not only gone against the authority of the council but also introduced an idea that disrupted the consistency of the doctrine of the Trinity. Soon both the Western church and Orthodox churches began to look upon one another as having deviated from Christian truth.

Other issues also became controversial. The medieval Western church increasingly banned the ordination of married men to the priesthood, customary in the Orthodox world. The Orthodox also regarded the Western preference for unleavened bread in the Eucharist as an unlawful custom. The two sides never reached any harmony because they followed different criteria of judgment: The papacy considered itself the ultimate judge in matters of faith and discipline, whereas the East invoked old tradition and the authority of councils, where the local churches spoke as equals.

It is often assumed that the anathemas (excommunications) exchanged in Constantinople in 1054 between the patriarch Michael Cerularius and papal legates marked the final schism. The schism, however, actually took the form of a gradual estrangement, beginning well before 1054 and culminating in the sack of Constantinople by Western Crusaders in 1204. This action introduced a new element of political bitterness into East-West Christian relations.

In the late medieval period, several attempts were made