Eastern Christianity - Church of The East

Church of The East

Historically, the Church of the East was the widest reaching branch of Eastern Christianity, at its height spreading from its heartland in Persian ruled Mesopotamia to the Mediterranean, India, and China. Originally the church of Sassanid Persia, the Church of the East declared itself independent of other churches in 424 and over the next century became affiliated with Nestorianism, a Christological doctrine advanced by Nestorius, Patriarch of Constantinople from 428 to 431, which had been declared heretical in the Roman Empire. Thereafter it was often known as the Nestorian Church in the West. Surviving a period of persecution within Persia, the Church of the East flourished under the caliphate and branched out, establishing dioceses throughout Asia.

After a period of expansion under the Mongol Empire, the church went into decline through the 14th century, and was eventually confined largely to its heartland in what is now Iraq, northeastern Syria,southeastern Turkey, northwestern Iran and to the Malabar Coast of India. In the 16th century dynastic struggles sent the church into schism, resulting in the formation of two rival churches. Two modern churches developed from the schism, the Chaldean Church, which entered into communion with Rome as an Eastern Catholic Church, and the Assyrian Church of the East,the followers of these two churches are almost exclusively ethnic Assyrians. In India, the local Church of the East community, known as the Saint Thomas Christians, experienced its own rifts as a result of Portuguese influence.