Orthodox Church. Major grouping of Christian churches, constituting, by full communion with each other, a single Church. The Orthodox Church claims direct descent from the Church of the apostles and of the seven ecumenical councils. The name ‘Eastern Orthodox’ (to be distinguished from ‘Oriental Orthodox’) arose from accidents of history and geography which led to a separation from ‘the West’; but Orthodoxy has in fact spread throughout the world.

The Orthodox Church comprises a number of autocephalous bodies in communion with one another: the ancient patriarchates of Constantinople, Alexandria, Antioch, and Jerusalem, and the Orthodox Churches of Russia, Serbia, Romania, Bulgaria, Georgia, Greece, Czechoslovakia, Poland, Cyprus, and Albania. In addition, there are autonomous churches (whose primate is under the aegis of one of the autocephalous churches) in Finland, Crete, Japan, and China, and missions yet to become autonomous in Korea and Africa. The oecumenical patriarch of Constantinople has a primacy of honour, but no universal jurisdiction to correspond to that of the pope.

The Orthodox Church traces its history back to the missionary work of Paul, and itself became missionary, achieving notably the conversion of the Slavs through the ‘apostles of the Slavs’, Cyril and Methodius. Russia became a Christian kingdom under St Vladimir in 988.

There was a progressive estrangement between Rome and Constantinople, partly on account of divergent liturgical usages and also because of the claims of the Roman papacy. There was a temporary schism under patriarch Photius, then a final one under Michael Cerularius in 1054. Attempts at reunion, notably at the Council of Florence (1439), have been ineffective.

After the fall of Constantinople (1453), the Church came under Muslim rule.

Orthodox doctrine proceeds from the Bible, the formulae of the seven ecumenical councils, and broadly from the writings of the Greek fathers. Many doctrines of more recent definition in the W., e.g. the nature of sacraments and the Immaculate Conception, are not laid down. On the other hand, constant and exclusive appeal to ancient authorities makes Orthodox theology inherently conservative.

The Orthodox liturgy (eucharist) is longer than the Western, and typically celebrated with greater ceremonial. Baptism is by immersion, and is followed by chrismation (see CHRISM). Icons are an essential part of the furnishing of a church building, and in houses are a focus of private prayers.

Parish priests are usually married, but may not marry after their ordination as deacon. Bishops, however, are always celibate, and therefore do not come from the parish clergy but from the ranks of monks. Besides providing bishops, monasticism has also provided the intellectual and spiritual centre of Orthodoxy, specifically in modern times at Mount Athos, but many theologians today are laypeople.

orthodox church. The eastern orthodox church dating from earliest Christian times has its centre at Constantinople (Istanbul), the residence of the ecumenical patriarch, who has primacy of honour over much of the ‘intricate tapestry’ of the Christian East, including the Greeks, Serbs, Bulgars, Georgians, and Russians. In 1995 there were c.190 million adherents world-wide. The earlier rupture with Syriac monophysite churches was followed by the break with Rome and the West (1054), which the crusades intensified. Orthodoxy has always been closely associated with temporal power. Priests are usually married, though bishops are always celibate. Icons are central to devotion, but at the heart of orthodox life is the mystery of the liturgy with its chanting and ceremonial in icon-lined churches—an experience of ‘heaven on earth’. Orthodoxy's greatest contribution to the West has been its mystical writings, ranging from 7th-cent. Symeon the New Theologian to the 18th-cent. Philokalia, and its practice of silent, contemplative prayer. British contacts with orthodoxy began with 16th-cent. merchants and Peter the Great's visit to England (1698). Since the 1950s orthodoxy has flourished in England with c.287,000 members (1995).

Revd Dr William M. Marshall

Or·tho·dox Church a Christian church or federation of churches originating in the Greek-speaking church of the Byzantine Empire, not accepting the authority of the pope, and using ancient forms of service.