Beginning of the Rome-Constantinople Schism
The beginning of the Rome-Constantinople Schism marks a significant historical division between the Eastern Orthodox Church, centered in Constantinople, and the Roman Catholic Church, based in Rome. This split can trace its roots back to the division of the Roman Empire in 395, which created a geographical and cultural separation between the two churches. As the Eastern Church adopted Greek language and culture, it became intertwined with the authority of the Byzantine emperor, while Rome maintained its apostolic primacy through the pope.
Over time, doctrinal disagreements arose, particularly regarding the nature of the Holy Spirit, clerical celibacy, and the use of leavened versus unleavened bread in the Eucharist. Tensions escalated significantly in 1054 when mutual excommunications occurred following a breakdown in dialogue between Pope Leo IX and Patriarch Michael Cerularius. Although the immediate cause of this schism involved specific liturgical practices, deeper historical grievances fueled ongoing mistrust and resentment.
The ensuing Crusades, initially intended to unite Christendom against external threats, further exacerbated the rift, particularly after the sack of Constantinople in 1204, which left a lasting scar on Byzantine memory and solidified the separation between the churches. This schism, characterized by cultural differences and doctrinal disputes, remains a pivotal moment in Christian history, illustrating the complexities of faith, politics, and identity in the medieval world.
Beginning of the Rome-Constantinople Schism
Date 1054
Locale Constantinople, Byzantine Empire
The schism between Christians in Rome and Christians in Constantinople intensified and reached its culmination after the conquest of Constantinople by the soldiers of the Fourth Crusade in 1204. The schism later weakened Christianity against the rise of Islam during the Turkish conquests of the fourteenth and fifteenth centuries.
Key Figures
Michael Cerularius (c. 1000-1059), patriarch of Constantinople, 1043-1058Leo IX (1002-1054), Roman Catholic pope, 1048-1054Urban II (c. 1042-1099), Roman Catholic pope, 1088-1099Constantine IX Monomachus (c. 980-1055), Byzantine emperor, r. 1042-1055Humbert of Silva Candida (c. 1000-1061), cardinal of Silva Candida and papal legateAlexius I Comnenus (1048-1118), emperor of Constantinople, r. 1081-1118Argyros (d. 1058), commander of Italy, Calabria, Sicily, and Paphlagonia, 1051-1058Bohemond I (c. 1052-1111), Norman adventurer, commander of the Normans against Byzantium
Summary of Event
The gradual alienation between the Eastern and Western Christian churches may be traced as far back as the physical division of the Roman Empire in 395, when the Eastern Church, with its capital in Constantinople, was separated from the Western Roman Church by the Theodosian line, a geographic demarcation that traversed the Balkan peninsula.
Founded in 330 by Emperor Constantine the Great (r. 306-337) and heavily influenced by Hellenic Greek culture, the Eastern Church adopted the Greek language and became the center of an empire in which church and state were equally under the authority of the Byzantine emperor, the representative of God on earth. Doctrinal matters were decided by ecumenical councils called by the emperor, which were attended by the bishops of the five patriarchal cities: Rome, Constantinople, Antioch, Alexandria, and Jerusalem. Of these Rome was considered the most important, since it was the see founded by Saint Peter. Constantinople, the residence of the emperor, was second in importance after Rome.
The weakening of the Latin-speaking Church based in Rome following the barbarian incursions of the fourth century meant that the Byzantines saw themselves as the legitimate heirs of the Roman Empire and the repository of the Christian tradition. As bishop of Rome, however, the pope maintained his primacy because of the apostolic foundation of his see.
Over time, disagreements between the two branches of Christianity developed, in part because of communication difficulties and also because of cultural differences between them. These differences touched on issues both of authority and doctrine. The concept of schism, a split within the Christian community, is distinguished from heresy, which is a division based on doctrinal differences.
Past schisms had developed between the churches, the most noteworthy being the Acacian schism of 483-518, in which Acacius, patriarch of Constantinople (471-489), was excommunicated for making concessions to the Monophysites, and that of 595, when Pope Gregory I (590-604) objected to the title of ecumenical patriarch being applied to the patriarch of Constantinople. Further ill-will developed in Rome when the Byzantines instigated the Iconoclastic Controversy under Emperor Leo III (r. 795-816), which was later condemned at the seventh ecumenical Council of Nicaea in 787. This estrangement was exacerbated by the papal crowning of Charlemagne (r. 800-814) as emperor of the Romans in 800 and subsequently, when attempts were made to substitute the primacy of the pope for that of the emperor.
A more serious doctrinal dispute was occasioned by the insertion of the filioque clause into the Nicene Creed, first proposed by the German popes elected after Emperor Otto I (r. 936-972) restored the Western Roman Empire. The filioque was inserted into the language approved at the Council of Nicaea concerning the procession of the Holy Spirit, which was believed to come from the Father. The addition of language indicating that it proceeded also from the Son, in Latin filioque, was considered heretical by the Eastern Church. A further area of disagreement touched on celibacy of the clergy, an innovation in the Roman Church imposed by the western Franks, and Latin condemnation of the use of leavened bread in the celebration of the eucharist by the Greeks.
Some date the Eastern schism from 1009, when the pope sent a copy of the creed with the filioque included to the patriarch Sergius II of Constantinople (1001-1019). From that date, the Byzantines no longer included the pope’s name in the diptychs of their Church. Nevertheless, practitioners of the Greek and Roman rites did not feel that the churches were in schism at that time.
The immediate cause of the controversy of 1054 was the refusal of Michael Cerularius, the patriarch of Constantinople, to countenance the use of unleavened bread in the communion ceremony as practiced in Byzantine territory in southern Italy. To the Greeks, the leaven in the bread was symbolic of the life of Christ. So Cerularius closed down churches using the Latin rite in Constantinople in 1052. Leo, the Eastern Orthodox archbishop of Ochrida, dispatched a letter of protest against the use of unleavened bread. The archbishop’s action outraged Pope Leo IX, who replied to the letter and demanded the submission of the patriarch to the primacy of Rome. After a further exchange of letters, the pope dispatched legates to Constantinople with a letter to Cerularius that was insulting in tone, as well as a more amicable one to the emperor.

Wishing to avoid controversy, Constantine IX Monomachus, the Byzantine emperor, cordially received the legates, headed by Cardinal Humbert of Silva Candida . Although Constantine proposed a compromise, it was unacceptable to Patriarch Michael Cerularius, who saw the views of the Romans as heretical. The papal legates composed a bull of excommunication, written in Latin, against the patriarch and all his supporters. After placing this document on the altar of the cathedral of Hagia Sophia in Constantinople, the legates left the city. When it was translated back into Greek, this bull was mistranslated, extending the excommunication against the entire Eastern Church. Cerularius used this pretext to recall the legates to Constantinople and imprison the supporters of Argyros, his archenemy in Italy. Cerularius also had the translators beaten and convened a holy synod to excommunicate the legates and pronounce anathema. His precipitate action outfaced the emperor of Constantinople, who wished to adopt a conciliatory policy toward Rome.
In the meantime, Pope Leo IX had died in 1054, thus invalidating the bull of excommunication. Confusion as to the implications of the actions of Humbert and Cerularius made it unclear whether a state of schism actually existed between the churches of Rome and Constantinople.
While these events were taking place, the Turks of Anatolia were continuing to threaten Christendom. Urban II, who was elected pope in 1088, and Alexius I Comnenus , emperor of Constantinople, were in accord on the need to form a crusade to resist the Turks. Although the emperor was hesitant to throw open the doors of his empire to armed soldiers from the West, he and Pope Urban II decided to pursue a Crusade. For his part, the pope saw a Crusade as a way to repair the rupture between the Eastern and Western churches. The Byzantine emperor reached an understanding that any formerly Byzantine cities captured by the Crusaders should revert to the empire. Unfortunately, this did not happen when Antioch, one of the five patriarch cities, was recovered by the Crusaders. Bohemond I, a Norman adventurer, kept the city in spite of his oath to Emperor Alexius I and nominated a Latin patriarch, exiling the Greek patriarch to Constantinople.
Significance
Nominally intended to recapture the Holy Land but more frequently causing pillage and destruction throughout the imperial realms of the Byzantines, subsequent Crusades only served to deepen the distrust of the Byzantine Greeks toward the adherents of the Latin Church. The Greeks maintained their unwillingness to recognize the primacy of the pope of Rome. This mutual bitterness reached a bloody culmination in 1182, when the Greeks massacred the population of the Latin colony of Constantinople, and again in 1185, when the Greeks of Salonika were in their turn massacred by the Normans. Because they attempted to negotiate with the Turks, the Byzantine Greeks were accused of treachery by the Latins. Bohemond I used this argument as a rationale for diverting the armies of the Fourth Crusade to attack Constantinople in 1204. The Crusaders sacked and plundered the city, massacred many of the inhabitants, destroyed churches, works of art, and architectural monuments, appointed a Latin patriarch, and founded Constantinople as a Latin empire.
Although the Greek rule of Constantinople was restored during the following century, this destruction of their beautiful city by fellow Christians remained in the Greek memory as an unforgivable transgression, and it doomed all subsequent attempts to reunify the Eastern and Western churches.
Bibliography
Angold, Michael. The Byzantine Empire, 1025-1204: A Political History. 2d ed. New York: Longman, 1997. This study focuses on political events and discusses the schism within that context. Maps, bibliography, index.
Chadwick, Henry. East and West: The Making of a Rift in the Church, from Apostolic Times Until the Council of Florence. New York: Oxford University Press, 2003. Explores the history of the Christian faith and its schisms from apostolic times—the first two centuries c.e.—through the Council of Florence in 1439, which attempted to unify the Eastern and Western Churches. Bibliography, index.
Hassan bin Talal, El. Christianity in the Arab World. New York: Continuum, 1998. A brief look at the schism from the Arab perspective. Also includes chapters on the iconoclastic controversy, the Nicene Creed, and Islamic influences on Christianity. Bibliography, index.
Luscombe, David, and Jonathan Riley-Smith, eds. The New Cambridge Medieval History. Vol. 4. New York: Cambridge University Press, 2004. This standard and often reprinted work focuses on the eleventh and twelfth centuries and discusses in part one the schism from the Roman point of view and the reform of the Western Church. Maps, bibliography, index.
Norwich, John Julius. Byzantium: The Apogee. New York: Alfred A. Knopf, 1996. A popular, highly readable account of the Byzantine Empire from 800 to 1081. Illustrations, bibliography, index.
Norwich, John Julius. Byzantium: The Decline and Fall. New York: Alfred A. Knopf, 1996. Continuation of the author’s account above, covering the period from the Crusades to the fall of the Byzantine Empire to the Turks in 1453.
Runciman, Steven. The Eastern Schism: A Study of the Papacy and the Eastern Churches During the Eleventh and Twelfth Centuries. 1955. Reprint. New York: AMS Press, 1983. The classic work on events leading up to the schism, reasons for the positions of each side, and the aftermath, focusing on the devastating impact of the schism for the Byzantine Empire. This study represents the Greek point of view. Bibliography, index.