Eastern Christianity

Eastern Christianity refers collectively to the Christian traditions which developed in Greece, the Balkans, the rest of Eastern Europe, Asia Minor, India, and the Middle East over several centuries of religious antiquity. Its division from Western Christianity has as much to do with culture, language, and politics as theology. A definitive date for the commencement of schism cannot be given (see East-West Schism), although conventionally, it is often stated that the Assyrian Church of the East became estranged from the church of the Roman Empire in the years following the Council of Ephesus (431), Oriental Orthodoxy separated after the Council of Chalcedon (451), and the split between the Church of Rome and what came to be called the Orthodox Church is usually dated to 1054 (often referred to as the Great Schism).

Families of churches
Eastern Christians have a shared tradition, but have also known division from one another over the centuries. Eastern Christianity can be described as comprising four families of churches.
 * The Eastern Orthodox accept seven Ecumenical Councils as defining their faith tradition (though many regard the councils of 879-80 and 1341-1351 as being the Eighth and Ninth Ecumenical Councils). The church is divided along national lines, made up of 14 or 15 national autocephalous bodies. Smaller churches are autonomous, and have a mother church that is autocephalous. Barring small schismatic bodies, Eastern Orthodox are united in communion with the Patriarch of Constantinople, though unlike in the Roman Catholic Church, this is a looser connection rather than a top-down hierarchy (see primus inter pares).
 * The Oriental Orthodox accept only three Ecumenical Councils, those of Nicea (AD 325), Constantinople (381), and Ephesus (431), especially rejecting the definitions of the Council of Chalcedon (451). Oriental Orthodoxy first developed on the eastern limit of the Byzantine Empire, particularly in Egypt and Syria, in reaction to Chalcedon. In those locations, there are also Eastern Patriarchs, but the rivalry between the two has largely vanished in the centuries since schism. There are autocephalous churches in full communion in Armenia, Eritrea, Ethiopia, and India as well.
 * The Assyrian Church of the East accepts only the Council of Nicaea and the First Council of Constantinople. Developing within the Persian Empire, further east, it rapidly took a different course from other Eastern Christians.
 * The Eastern Catholic (or "Uniat[e]") family of churches are in communion with the Roman Catholic Church (of which Eastern Catholics form around 2%), but are rooted in the traditions of Eastern Christianity. For example, their priests need not be celibate, and their parish priests administer the sacrament of confirmation to newborn infants immediately after baptism, via the rite of chrismation; the infants are then administered Holy Communion. Many of these churches were originally part of one of the above families and are closely related to them by way of ethos and liturgical practice.
 * In addition to these four mainstream branches, there are a number of much smaller groups which, like Protestants, are dissenters from the dominant tradition in their area, but are usually not referred to as Protestants because they lack historical ties to the Reformation, and usually lack a classically Protestant theology. Most of these are either part of the more traditional Old Believer movement, which arose from a schism with Russian Orthodoxy, or the more radical "Spiritual Christianity" movement. The latter includes a number of diverse "low-church" groups, from the Bible-centered Molokans to the self-mutilating Skoptsy. None of these groups are in communion with the mainstream churches listed above, aside from a few Old Believer parishes in communion with the Russian Orthodox Church Outside Russia (which is itself relatively isolated).