Eastern Christianity refers collectively to the Christian traditions which developed in Greece, the Near East and Eastern Europe. Its division from Western Christianity is as much to do with culture and politics as theology; a definitive date for the commencement of schism cannot be given.

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 (though many regard the councils of 879-80 and 1341-1351 as being the Eighth and Ninth Ecumenical Councils). Most Eastern Orthodox are united in communion with the Patriarch of Constantinople, though unlike in the Roman Catholic Church, this is not a touchstone of Orthodoxy or Catholicity.
• The Oriental Orthodox accept only the first three Ecumenical Councils, particularly rejecting the fourth, the Council of Chalcedon. Oriental Orthodoxy first developed on the eastern limit of the Byzantine Empire, particularly in Egypt and Syria.
• The Assyrian Church of the East accepts only the Council of Nicea. Developing within the Persian Empire, further east, it rapidly took a different course from other Eastern Christians.
• The Eastern Catholic family of churches are a part of 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, and the infants are then allowed to receive communion. Many of these churches were originally part of one of the above families.

There are also a few small Eastern Christian churches that do not fit into this scheme.