Eastern Orthodox Church

The Eastern Orthodox Church, officially the Orthodox Catholic Church,[6][7][8][9] is the second-largest Christian church,[lower-alpha 1][10] with approximately 220 million baptised members.[11][5][12] It operates as a communion of autocephalous churches, each governed by its bishops in local synods.[12] The church has no central doctrinal or governmental authority analogous to the bishop of Rome (Pope), but the ecumenical patriarch of Constantinople is recognised by all bishops as primus inter pares ("first among equals") and regarded as the representative and spiritual leader of Eastern Orthodox Christians.[13][14][15][16][17] As one of the oldest surviving religious institutions in the world, the Eastern Orthodox Church has played a prominent role in the history and culture of Eastern and Southeastern Europe, the Caucasus, and the Near East.[18]

Eastern Orthodox Church
TypeEastern Christian
ScriptureSeptuagint, New Testament
TheologyEastern Orthodox theology
Primus inter paresEcumenical Patriarch Bartholomew I
RegionSoutheast Europe, Eastern Europe, Cyprus, Georgia[1]
LanguageKoine Greek, Church Slavonic, vernacular[2][3][4]
LiturgyByzantine (nearly ubiquitous); also Western
FounderJesus Christ, according to
sacred tradition
Origin1st century, according to
sacred tradition
Judea, Roman Empire, according to
sacred tradition
SeparationsOld Believers (17th century)
True Orthodoxy (1920s)
Members220 million[5]
Other name(s)Orthodox Church, Orthodox Christian Church
Christ Pantocrator, 6th century, Saint Catherine's Monastery, Sinai; the oldest known icon of Christ, in one of the oldest monasteries in the world

Eastern Orthodox theology is based on holy tradition, which incorporates the dogmatic decrees of the seven ecumenical councils, the Scriptures, and the teaching of the Church Fathers. The church teaches that it is the one, holy, catholic and apostolic church established by Jesus Christ in his Great Commission,[19] and that its bishops are the successors of Christ's apostles.[20] It maintains that it practices the original Christian faith, as passed down by holy tradition. Its patriarchates, reminiscent of the pentarchy, and other autocephalous and autonomous churches, reflect a variety of hierarchical organisation. It recognizes seven major sacraments, of which the Eucharist is the principal one, celebrated liturgically in synaxis. The church teaches that through consecration invoked by a priest, the sacrificial bread and wine become the body and blood of Christ. The Virgin Mary is venerated in the Eastern Orthodox Church as the God-bearer, honored in devotions.

The Eastern Orthodox Church shared communion with the Roman Catholic Church as the state church of Rome until the East–West Schism in 1054, which was the culmination of mounting theological, political, and cultural disputes, particularly over the authority of the pope. Before the Council of Ephesus in AD 431, the Church of the East also shared in this communion, as did the various Oriental Orthodox Churches before the Council of Chalcedon in AD 451, all separating primarily over differences in Christology.

The majority of Eastern Orthodox Christians live mainly in Southeast and Eastern Europe, Cyprus, Georgia, and parts of the Caucasus region, Siberia, and the Russian Far East. Roughly half of Eastern Orthodox Christians live in the former Soviet Union, mostly Russia.[21][22] There are also communities in the former Byzantine regions of Africa, the Eastern Mediterranean, and in the Middle East, which are decreasing due to forced migration driven by increased religious persecution.[23][24] Eastern Orthodox communities are also present in many other parts of the world, particularly North America, Western Europe, and Australia, formed through diaspora, conversions, and missionary activity.