Abstract
Christianity spread into Mesopotamia no later than the mid-second century. By the early third century, Christian communities had been founded in Persian territory, outside the Roman Empire altogether. The ancient Eastern Christian church has traditionally been known as the “Nestorian” Church, but, like so many Christian church names, it was pinned on them by their ecclesiastical enemies and is rejected by the church itself. Several other ancient Eastern Christian churches originated in the fallout from the Council of Chalcedon: the Armenian Apostolic Church; the Coptic Orthodox Church in Egypt. In the fifth century, the dissenters against Chalcedon represented a large segment of Christians along the eastern rim of the Roman Empire and beyond it, Egypt, and Ethiopia. Orthodox Christians generally reject the Eastern Catholic churches and view them as an obstacle to Catholic–Orthodox reunion. In India, the Malankara Orthodox Syrian Church claims continuity with “Nestorian” communities that settled in the south of India no later than the sixth century.