Byzantine Religion and the Orthodox Church

If any single force defined the Byzantine Empire, it was religion. The Byzantine state was, from its foundation by Constantine in the fourth century until its fall in 1453, the only major Christian empire in the world. The Eastern Orthodox Church, which emerged from the crucible of late antiquity in Constantinople rather than in Rome, was the spiritual and ideological core of Byzantine civilization. Emperors were crowned by the church, laws were issued in the name of the Trinity, wars were fought against Christian heretics as well as against Muslim and pagan enemies, and the rhythms of daily life were governed by the liturgical calendar.

This pillar explores the full scope of Byzantine religious life: the doctrines and councils that defined orthodoxy, the liturgy that filled the great churches of the empire, the monks and monasteries that preserved learning and resisted imperial excess, the saints whose relics and miracles structured popular devotion, and the long, slow process by which the Christian East drifted apart from the Christian West in the event known as the Great Schism of 1054.

The Christian Roman Empire

Constantine and the Conversion of the State

The Christianization of the Roman Empire was a long, uneven process, but its defining moment came with the conversion of Emperor Constantine I in 312 AD and the Edict of Milan, which granted legal status to Christianity throughout the empire. Constantine’s vision at the Milvian Bridge, recorded by Eusebius, was the founding myth of the new Christian Roman state. By the time he founded Constantinople in 330, the new city was conceived as a Christian capital from the outset, with churches replacing temples as the principal buildings of public devotion.

The fourth century was decisive for the formation of Christian doctrine. The Council of Nicaea in 325, convoked by Constantine, produced the first ecumenical creed, declaring Christ to be “of one substance” with the Father and condemning Arianism. The Council of Constantinople in 381 expanded this creed into the form that would become the Nicene-Constantinopolitan Creed, recited in Orthodox churches to this day. Theodosius I, ruling from Constantinople, made Nicene Christianity the official religion of the empire in 380, ending the brief experiment of religious pluralism that had characterized the late Roman state.

The relationship between church and state, between priest and emperor, was from the beginning a delicate one. Constantine summoned councils and enforced their decisions, but he also recognized the spiritual authority of bishops. This caesaropapism, the claim of the emperor to supreme authority in ecclesiastical as well as civil matters, was a defining feature of Byzantine political theology and would be contested at every turn by monks and bishops who believed that the church must remain free to govern itself.

The Ecumenical Councils

Between 325 and 787, seven ecumenical councils met to define orthodox Christianity. The first two, Nicaea (325) and Constantinople (381), established the doctrine of the Trinity against Arianism and Macedonianism. The third, Ephesus (431), defined Mary as Theotokos, “God-bearer,” against Nestorianism. The fourth, Chalcedon (451), defined Christ as fully God and fully man in two natures against Monophysitism.

The Monophysite controversy was particularly painful. The Council of Chalcedon was rejected by the non-Greek-speaking eastern provinces, including Egypt, Syria, and Armenia, leading to a schism that would persist for centuries and that weakened the empire in the seventh century, just as the Arab invasions were beginning. Later councils, the Fifth (Constantinople II, 553) and the Sixth (Constantinople III, 680–681), attempted to reconcile Monophysites by clarifying Christ’s two wills, but the schism never fully healed.

The bluntness of the disagreement is best caught in the primary sources. Severus of Antioch, the Monophysite patriarch of the late fifth and early sixth centuries, complained that the Chalcedonian definition of “two natures” was little more than Nestorianism in disguise — a clever way, he thought, of saying that Christ was two people rather than one. The Chalcedonians replied, with some justice, that Severus’s own formulation made Christ’s humanity a husk around a divine core, which was the original Arian position. Each side thought the other was destroying the Incarnation; neither was entirely wrong.

The seventh council, Nicaea II in 787, restored the veneration of icons after the first phase of Byzantine Iconoclasm. Iconoclasm was both a religious controversy and a political assertion. Emperor Leo III banned icons in 726, claiming that they were idols. The defenders of icons, including John of Damascus and the monastic party, argued that the veneration of images was not idolatry but a legitimate extension of the doctrine of the Incarnation. The final restoration of icons in 843, the so-called Triumph of Orthodoxy, is still celebrated annually in the Orthodox Church as a major feast day.

The Great Schism of 1054

The most consequential event in Byzantine religious history was the gradual separation of the Eastern and Western churches, traditionally dated to 1054 but actually the result of centuries of growing apart. The theological, liturgical, and political differences between Rome and Constantinople had been accumulating since the fourth century.

Theological disputes centered on two issues. The first was the Filioque, the addition of the phrase “and the Son” to the Western version of the Nicene Creed, stating that the Holy Spirit proceeds from the Father “and the Son.” The Eastern churches argued that this addition was illegitimate, having been made without ecumenical consent, and theologically misleading, since it seemed to subordinate the Spirit to the Son. The second was papal authority. The Roman popes, following Leo I and Gregory the Great, claimed universal jurisdiction over the Christian church. The Byzantine patriarchs, while recognizing the pope’s primacy of honor, rejected his claim to universal jurisdiction.

Liturgical differences compounded the theological ones. The Eastern rite, derived from the liturgy of St. John Chrysostom and the liturgy of St. Basil the Great, was celebrated in Greek (with vernacular variations), used leavened bread, and gave communion to the laity in both bread and wine. The Western rite, codified in the Roman Missal after the reforms of Gregory VII, was celebrated in Latin, used unleavened bread, and gave communion to the laity in bread alone. Bishops in the East were required to be celibate, but priests could marry before ordination. Priests in the West were required to be celibate.

The political context was equally important. The papacy and the Byzantine emperor had competing interests in southern Italy, the Balkans, and the Holy Land. As the empire weakened in the eleventh century, the popes increasingly looked to the rising powers of Western Europe, especially the Normans and the Franks, as natural allies. In 1054, the papal legate Humbert of Silva Candida walked into the Hagia Sophia and placed a bull of excommunication on the altar, excommunicating Patriarch Michael Cerularius. Cerularius responded in kind. Although the mutual excommunications were lifted in 1965, the schism has never been formally healed and remains the central reality of Eastern Christian history.

The Patriarchate of Constantinople

The head of the Byzantine church was the Ecumenical Patriarch of Constantinople, who ranked next to the emperor in prestige and authority. The patriarch’s seat was in the Phanar district of Constantinople, the source of the modern Greek term “Phanar” as shorthand for the patriarchate. The patriarch was responsible for the spiritual life of the empire’s capital and had jurisdiction, sometimes disputed, over a large part of the Eastern Christian world.

The relationship between patriarch and emperor was complex. The emperor claimed the right to appoint and sometimes to depose the patriarch, and presided over church councils. But the patriarch also possessed a sacred authority, derived from apostolic succession, that the emperor could not grant or revoke. Conflicts between them were frequent, and they often resolved around the question of whether the emperor’s authority extended to matters of doctrine. The most famous such conflict, the Iconoclast controversy, ultimately resolved in favor of the church’s spiritual independence on matters of doctrine, even as the emperor retained the practical power to enforce decisions.

Byzantine Liturgy

The Byzantine liturgy was the most elaborate liturgical tradition in medieval Christianity. The principal service, the Divine Liturgy, was celebrated each Sunday and on major feasts in every parish church. The most commonly used form was the Liturgy of St. John Chrysostom, attributed to the great preacher who served as patriarch of Constantinople in the late fourth century. The Liturgy of St. Basil the Great was used ten times a year, especially during Lent.

The structure of the Divine Liturgy included the Proskomedia, the preparation of the bread and wine; the Liturgy of the Catechumens, including scripture readings, the chanting of psalms, and the sermon; and the Liturgy of the Faithful, including the Creed, the Anaphora (the Eucharistic prayer), and communion. The entire service was sung, with parts assigned to the priest, the deacon, the choir, and the congregation. The use of incense, icons, candles, vestments, processions, and chanting made the Byzantine liturgy a total sensory experience, designed to evoke the worship of heaven.

The temporal cycle of the Byzantine year included not only the feasts of the movable calendar (centered on Pascha, Easter) but also the fixed cycle of saints’ feasts and the Great Feasts of the church. The Twelve Great Feasts, including the Nativity of the Virgin, the Exaltation of the Cross, the Nativity of Christ, the Theophany, the Presentation, the Annunciation, the Transfiguration, and the Dormition, structured the religious life of every Byzantine Christian.

Hymns played a central role in Byzantine worship. The greatest of these was the Akathist Hymn, a long poem to the Virgin Theotokos, traditionally attributed to Patriarch Sergius of Constantinople in thanks for the divine protection of the city in 626. The Akathist is still sung in Orthodox churches during Lent and is one of the most beloved treasures of Byzantine sacred music.

Monasticism

Byzantine monasticism was the spiritual engine of the church. From the desert fathers of the fourth century, including St. Anthony the Great and St. Pachomius, to the great monasteries of Constantinople and the Holy Mountain, monasticism shaped Byzantine religious life profoundly.

The two basic forms of Byzantine monasticism were eremitic (solitary) and cenobitic (communal). The earliest monks, including St. Anthony, were hermits living in the Egyptian desert. By the fifth century, communal monasticism had become dominant, with the Rule of St. Basil the Great providing the standard text. The most important monasteries of the Byzantine world included Studios in Constantinople, founded in 462, which gave its name to the principal Byzantine chant tradition; the great monastery of the Holy Mountain, Mount Athos; and dozens of houses in Cappadocia, Egypt, Palestine, and the Holy Land.

Monks were far more than contemplative figures. They were the conscience of the empire, often opposing imperial policy in matters of doctrine. The monastic party led the resistance to Iconoclasm, fought against the union with Rome attempted by the Palaiologan emperors, and produced many of the greatest theologians, historians, and artists of the Byzantine world. The scholar-monks of the late empire, especially those of the hesychast tradition, defended the Orthodox doctrine of the uncreated light of Tabor against the attacks of the humanist philosopher Barlaam of Calabria in the fourteenth century.

The Saints and Popular Devotion

The saints of Byzantium were the intercessors between ordinary Christians and God. The cult of the saints was the most popular and pervasive form of Byzantine religious practice. Every city, every church, every profession had its patron saint. Pilgrims traveled to the great shrines, including the Church of the Holy Apostles in Constantinople, the church of the Holy Sepulchre in Jerusalem, and the great monastic shrines of the Holy Mountain and of Sinai.

Relics, the physical remains of the saints, were believed to possess miraculous powers and were the most valuable possessions of a church. The emperor himself might lead processions bearing relics in times of crisis. The translation of relics from the Holy Land to Constantinople, beginning in the fourth century, was a deliberate imperial policy, and the great collection of relics in the Church of the Holy Apostles made Constantinople a kind of second Jerusalem.

The cult of the Virgin Mary, the Theotokos, was central to Byzantine piety. Mary was venerated as the Mother of God, the protectress of Constantinople, and the intercessor for sinners. The most important Marian feasts, the Annunciation, the Dormition, and the Nativity of the Virgin, were celebrated throughout the empire. The Hodegetria icon was believed to be painted by St. Luke himself and was carried in procession at the start of every imperial campaign.

The Icon and Sacred Space

The iconostasis, the screen of icons separating the nave from the sanctuary, was one of the most distinctive features of Byzantine church architecture. Although the iconostasis developed gradually from a low barrier in the early Byzantine period to a full wall of icons by the fifteenth century, it always served to mark off the holy place from the worshipping congregation while allowing them to see the icons of Christ, the Virgin, and the saints.

The arrangement of the iconostasis was standardized over time. The Royal Doors in the center are flanked by icons of the Annunciation. To the right of the Royal Doors is the icon of Christ, and to the left is the icon of the Virgin. On the deacon’s doors at the ends of the screen are typically icons of archangels, often Michael and Gabriel, the warrior princes of heaven. Above the screen are the icons of the Last Supper, the Pantokrator, the Twelve Great Feasts, and the prophets.

The theology of icon veneration, articulated by John of Damascus, Theodore the Studite, and others, was central to Byzantine identity. The icon was not worshipped in itself but as a window to the prototype. The icon made present the person depicted. The rejection of icons was a sign of heresy; the defense of icons was the mark of true Christian belief.

The Long Reach of Byzantine Religion

Byzantine religion was never confined to the empire. Missionaries from Constantinople carried Orthodox Christianity to the Slavs, beginning with the mission of Saints Cyril and Methodius to the Great Moravian Empire in the ninth century, and continuing with the Christianization of Bulgaria in 864, of Serbia in the ninth century, and of Rus in 988. The Cyrillic alphabet, developed by followers of Cyril and Methodius, became the script not only of the Slavic Orthodox churches but also of the languages of nations that were not always politically aligned with Byzantium.

After the fall of Constantinople, the Byzantine legacy in Russia and the Balkans continued. The Russian Orthodox Church, the Romanian Orthodox Church, the Bulgarian Orthodox Church, the Serbian Orthodox Church, and the Orthodox Church of Albania all claim apostolic succession from the Byzantine patriarchate. The Greek Orthodox Patriarchate of Jerusalem still guards the holiest sites of Christianity. The Ecumenical Patriarchate of Constantinople, although reduced in territorial extent, remains the symbolic first see of Orthodox Christianity.

The Byzantine influence on Western Christianity, while obscured by the trauma of the Crusades and the eventual conquest of Byzantium, was also real. The monastic tradition, the theological method, the liturgical calendar, and the iconographic conventions of Western Christianity were all shaped in dialogue with the East. The Byzantine legacy remains one of the most powerful forces in the history of Christian civilization.

What to Read Next

The religion of Byzantium was not a marginal element of the civilization. It was the civilization. The state, the law, the art, the calendar, the music, the architecture, the relations with neighbours, and the very sense of identity of the Byzantines were all structured by their Orthodox Christian faith. The cluster and long-tail articles in this section trace the doctrines, the liturgy, the monasticism, and the saints that made the Byzantine religious world what it was.

Sources & Further Reading

There is no good one-volume English introduction to Byzantine religion; the field is split between surveys of theology and surveys of the institutional church. For the theology, John Meyendorff, Imperial Unity and Christian Divisions (St. Vladimir’s Seminary Press, 1989) is still the most reliable single-volume guide. For the institution and the liturgy, Runciman’s The Eastern Schism (1955) is a generation old but still the best narrative; for something more recent, see Andrew Louth, Greek East and Latin West: The Church AD 681–1071 (St. Vladimir’s Seminary Press, 2007), and Alexander Schmemann, Introduction to Liturgical Theology (St. Vladimir’s Seminary Press, 1966 — reissued in several later editions). For the Great Schism specifically, the documents are translated in The Treatise on the Procession of the Holy Spirit by St. Photios and in the responses of Cardinal Humbert; Steven Runciman’s The Eastern Schism (1955) remains the most readable account. For the most recent work, A. Edward Siecienski’s The Filioque: A History of a Doctrinal Controversy (Oxford UP, 2010) is a good place to start.

Related Articles

• The Great Schism of 1054 — the split between East and West
• Byzantine Monasticism — the monks who shaped the empire
• Byzantine Liturgy and Worship — the prayers of the Christian East
• Saints in Byzantine Tradition — the intercessors in heaven
• The Akathist Hymn — the supreme Marian hymn
• The Iconostasis: Evolution and Meaning — the sacred screen
• Mount Athos: The Holy Mountain — the monastic republic
• Byzantine Icon Veneration and Theology — the defense of images
• The Ecumenical Patriarchate of Constantinople — the first see of Orthodoxy
• History of the Byzantine Empire — the historical context