The Oriental Orthodox Churches are Eastern Christian churches adhering to Miaphysite Christology, with approximately 60 million members worldwide. The Oriental Orthodox Churches are part of the Nicene Christian tradition, and represent one of its oldest branches. As some of the oldest religious institutions in the world, the Oriental Orthodox Churches have played a prominent role in the history and culture of Armenia, Egypt, Eritrea, Ethiopia, Sudan, Western Asia and India. As autocephalous churches, their bishops are equal by virtue of episcopal ordination. Their doctrines recognize the validity of only the first three ecumenical councils. The Oriental Orthodox Churches are composed of six autocephalous churches: the Coptic Orthodox Church of Alexandria, the Syriac Orthodox Church of Antioch, the Armenian Apostolic Church, the Malankara Orthodox Syrian Church, the Ethiopian Orthodox Tewahedo Church, and the Eritrean Orthodox Tewahedo Church. They consider themselves to be the one, holy, catholic, and apostolic Church founded by Jesus Christ in his Great Commission, and that its bishops are the successors of Christ's apostles. Three rites are practiced by the churches: the western-influenced Armenian Rite, the West Syriac Rite of the Syriac Church and the Malankara Church of India, and the Alexandrian Rite of the Copts, Ethiopians and Eritreans. Oriental Orthodox Churches shared communion with the Roman Church before the Council of Chalcedon in 451 AD, and with the Church of the East until the Council of Ephesus in AD 431, separating primarily over differences in Christology. The majority of Oriental Orthodox Christians live in Egypt, Ethiopia, Eritrea, India, Syria, Turkey and Armenia, with smaller Syriac communities in Western Asia—decreasing due to persecution. There are also many in other parts of the world, formed through diaspora, conversions, and missionary activity. Name and characteristics The name "Oriental Orthodox Churches" was coined for the Conference of Addis Ababa in 1965. At the time there were five participating churches, the Eritrean Church not yet being autocephalous. Other names by which the churches have been known include Old Oriental, Ancient Oriental, Lesser Eastern, Anti-Chalcedonian, Non-Chalcedonian, Pre-Chalcedonian, Miaphysite or Monophysite, although the Church of the East is equally anti-, non- and pre-Chalcedonian. The Roman Catholic Church has referred to these churches as "the Ancient Churches of the East". Theology and ecclesiology The Oriental Orthodox Churches are distinguished by their recognition of only the first three ecumenical councils during the period of the State church of the Roman Empire: the First Council of Nicaea