The roots of the schism, or division, between the Latin Church of the West and the Greek Orthodox Church of Byzantium predated the crusade era, but the first four major crusades (1096-1204) made the rupture clear and final. Pope Urban II set in motion the First Crusade (1096-1099) because he desired to aid his fellow Christians in the East and apparently hoped that this action would bring the Latin and Greek churches closer together under papal leadership. The opposite was the case.
Multiple factors—cultural, political, and ecclesiological— precipitated the schism. The most basic was ecclesiology: the manner in which the West and Byzantium envisioned the nature and functioning of the universal church. The central ecclesiological issue was papal primacy. Byzantine Christians regarded the pope as first among equals within a pentarchy consisting of the patriarchates of Rome, Constantinople (mod. Istanbul, Turkey), Alexandria, Antioch (mod. Antakya, Turkey), and Jerusalem. These were the collective guardians of the orthodox faith, as defined in the seven ecumenical councils that met between 325 and 787. Western Christians, especially after the mid-eleventh century, understood papal primacy to mean that submission to the unique authority of the Roman pope was the determinant of orthodoxy and membership in the universal church.
Although the ideology of radical papal primacy, as well as the crusades, arose out of the so-called Gregorian Revolution of the eleventh century, the Roman and Byzantine churches had moments of misunderstanding and separation long before then. They were temporarily divided during the Aca- cian Schism (484-519), when the papacy rejected the efforts of Emperor Zeno and Patriarch Acacius to accommodate the Monophysite Christians of Egypt, whose doctrine that Christ had a single, divine nature had been condemned at the Council of Chalcedon in 451. Two centuries later, the Iconoclastic Controversy (726-843) drove a deep wedge between papal Rome and imperial Constantinople, but even though the Byzantine Church was officially iconoclastic for most of these twelve decades, its lower clergy and laity shared the West’s strong rejection of iconoclasm. When Empress Theodora permanently restored the practice of icon veneration in 843, the two churches reestablished communion.
Despite reunion, the Iconoclastic Controversy permanently widened an ever-growing cultural and political chasm. In its moment of crisis, the papacy turned to the Franks—a radical departure from earlier policies—and the result was the coronation of Charlemagne as the Holy Roman, or Western, emperor. It was Charlemagne’s court that introduced the practice of adding the word Filioque (“and from the Son”) to the phrase in the Nicene Creed “the Holy Spirit... who proceeds from the Father.” Although the papacy initially rejected this Carolingian addition to the creed and did not accept it until around 1014-1015, the innovation became a matter of controversy between Eastern and Western Christians almost immediately.
Filioque figured prominently in the list of erroneous customs that Photios, patriarch of Constantinople, leveled against the Latin Church during the next major ecclesiastical breach, the Photian Schism (863-880). This controversy, although amicably resolved, pointed out the growing differences in ecclesiological ideologies and traditions that separated Eastern and Western Christians. Simply put, Pope Nicholas I’s vision of papal primacy led him to intervene in the internal affairs of the Byzantine Church, namely, the issue of Photios’s contested promotion to the patriarchate, and that intervention aroused resistance in Constantinople.
Photios died in communion with Rome, but the schism that bears his name was a prologue to greater misunderstandings engendered during the eleventh century in the wake of papal reform. The year 1054 is often identified as the definitive moment of schism owing to supposed sentences of excommunication that the churches of Rome and Constantinople laid on one another. In fact, the events of 1054 did not usher in a recognized and accepted split between these two churches, but they were symptoms of essential differences.
In 1050 Pope Leo IX and Patriarch Michael I Keroular- ios quarreled over the papacy’s attempt to impose Latin practices on the Greek Christians of southern Italy and the patriarch’s retaliatory action of forcing Byzantine rituals on Latin churches in Constantinople. Chief among the controverted issues were clerical celibacy, Filioque, the Latin practice of fasting on Sunday, and the Latin use of unleavened bread (Lat. azymes) for the Eucharist. Despite this disagreement, in 1054 Pope Leo sent several legates to Constantinople to arrange an alliance with Emperor Constantine IX Monomachos against the Normans of southern Italy. The legation’s chief delegate, Cardinal Humbert of Silva Candida, soon engaged in heated debates with several Byzantine churchmen regarding their respective ecclesiastical traditions, and in the process both parties lost all sense of moderation. On 16 July 1054 Humbert laid on the altar of the Church of Hagia Sophia a bull excommunicating Michael and his supporters. The patriarch retaliated by convening a synod that excommunicated the legates. Neither excommunication was directed against an entire church, and there is no evidence of any sense of cataclysmic schism on either side, even though the two churches had, in fact, become separate entities.
In 1073, two years after the great defeat of the Byzantines by the Saljûq Turks at Mantzikert and the contemporaneous loss of Byzantium’s last holdings in southern Italy to the Normans, Emperor Michael VII Doukas appealed to Pope Gregory VII for aid. In February 1074 Gregory sent a letter to William, count of Upper Burgundy, urging him to send troops to Italy to defend papal lands against the Normans, and then went on to note that once the Normans were pacified, Gregory hoped to cross to Constantinople to aid the Christians who were oppressed by Muslim attacks. The following month the pope issued a general summons to all Latin Christians to aid their siblings in the East, and in December Gregory informed King Henry IV of Germany that 50,000 men stood ready to march east with Gregory at their head. Nothing immediate came of this plan due to the Investiture Controversy that broke out in 1075-1076. The dream, however, of aiding fellow Christians in the East through armed intervention remained alive within papal reform circles until it was transformed into the First Crusade by Pope Urban II.
As early as 1089 Pope Urban and Emperor Alexios I Komnenos discussed closer ecclesiastical relations. Urban lifted a ban of excommunication that Pope Gregory had laid on Alexios and his predecessor for deposing Emperor Michael VII and requested that his name be entered into the diptychs of Constantinople, which listed all Orthodox prelates with whom the Byzantine Church was in communion. A synod convened by the emperor that year could find no reason for the omission (possibly the synod chose to be diplomatically ignorant) and invited the pope either to come to Constantinople to discuss their differences or to send a statement of faith. Showing an equal sense of diplomacy, Urban did not press the issue and sent no credal statement, probably realizing that Filioque would be a sticking point. He remained uncommemorated in the prayers of the Byzantine Church, but his relations with Alexios remained warm.
On the eve of the First Crusade, therefore, high-ranking church leaders in both Rome and Constantinople were aware that differences separated them, and that for some time they had not been in official communion. At the same time, they seem to have believed they still were members of the same Christian family and that their differences were not irremediable or the result of the other party’s depravity. On the popular level there seems to have been even less awareness of separation. The crusades changed that.
A number of leaders of the First Crusade, including the papal legate Adhemar of Le Puy, sought to weld Byzantine and crusader forces into a single Christian army, but the military, logistical, and personal strains proved too great. Crusaders and Byzantine soldiers clashed in the Balkans and outside the gates of Constantinople, and once they were in Anatolia, misunderstandings multiplied. Antioch, a Byzantine Christian city, became a particular center of growing estrangement. Emperor Alexios’s failure to come to the crusaders’ aid during their long struggle to seize and then defend Antioch contributed to a growing sentiment within crusader circles that the Greeks were faithless. On their part, the Byzantines looked upon Bohemund of Taranto’s conversion of Antioch into a crusader principality in 1098 and his forcing the Greek patriarch of the city into exile in 1100 and replacing him with a Latin churchman as evidence of Frankish perfidy. Rival Byzantine patriarchs- in-exile of Antioch became voices and rallying points against this invasion by Christians from the West, who were now perceived as less than orthodox. Bohemund I of Antioch further contributed to the growing hostility between Byzantines and Latins when he convinced Pope Paschal II in 1105 to authorize a crusade against Alexios I, a putative enemy of the Frankish states ofOutremer. Although Bohemund’s crusade of 1107 failed, it fomented new animosity between Byzantines and Latins.
The remainder of the twelfth century witnessed growing hostility and a deepening sense of schism on both sides. Many Westerners ascribed the failure of the Second Crusade (1147-1149) to Greek treachery. The massacre of Constantinople’s Latin residents in 1182 and the alliance of Emperor Isaac II Angelos with Saladin during the early stages of the Third Crusade (1189-1192) only added to the Latin West’s general belief that the Greeks were no better than the Saracens. On their part, Byzantines could point to the many instances of Western attacks on their lands and persons, including William II of Sicily’s massacre of the Byzantines of Thessalonica in 1185, as proof of Western barbarism.
On the eve of the Fourth Crusade (1202-1204), specifically between the spring of 1198 and early summer 1202, eight missions and twelve letters passed between the Byzantine imperial court and the Curia of Pope Innocent III, as Emperor Alexios III Angelos and the pope tried to negotiate an alliance. The negotiations failed because Innocent demanded submission of the Byzantine Church to papal authority as a necessary prelude to any political accommodation.
The pope did not direct the Fourth Crusade against Constantinople and actually tried to prevent its diversion. However, when he learned of the city’s capture and the installation of a Latin emperor, he rejoiced, perceiving it to be fitting punishment for the Greeks’ willful separation from the Roman Church and a God-given opportunity to bring these fallen siblings back into the fold. Most Westerners seem to have agreed with this assessment. From the Byzantine perspective, the brutal sack of the city, the subsequent conquest of large areas of the Byzantine Empire by crusader-adven- turers, and the papacy’s largely unsuccessful but vigorous attempt to Latinize a captive Greek Church were all humiliating but temporary burdens to be borne.
In response, the Byzantines established several empires in exile. The most important was at Nicaea (mod. Iznik, Turkey) in Asia Minor, where the Byzantine patriarchate of Constantinople was also reestablished. With rival Latin and Greek emperors and patriarchs residing in Constantinople and Nicaea, the schism was complete.
In 1261 the Nicaean emperor Michael VIII Palaiologos recaptured Constantinople, but the threat of attack by Westerners who wished to restore the Latin empire of Constantinople forced him into the policy of offering church union in return for the papacy’s support. At the Second Council of Lyons (1274), imperial representatives submitted the Byzantine Church to the papacy. Virulent opposition within Byzantium and shifting fortunes in the West combined to defeat this union, which Emperor Andronikos II Palaiologos repudiated in 1282.
Another threat, this time from the Ottoman Turks, again drove a Byzantine emperor, John VIII Palaiologos, to offer church union in exchange for Western assistance. In 1439 at the Council of Florence, Patriarch Joseph II submitted to Roman papal authority. Once again, however, official imperial policy was defeated by popular opposition. Although the union existed on paper until its repudiation in 1484, it was a phantom union from the start.
The so-called union did produce the Crusade of Varna (1444), which failed to stem the Ottoman tide. Constantinople fell to the Ottoman Turks on 29 May 1453. Under Turkish rule the Byzantine Church grew ever more adamant in its determination to be a bulwark of Christian orthodoxy against the infidelity of its Muslim lords and the perceived heresies of the Latin West.