Nestorianism

Nestorianism is the name usually given to the Church of the East. Its namesake Nestorius was Patriarch of Constantinople; after the Council of Ephesus condemned his teaching in 431, the church of the Sasanian Persian empire held to it, and its patriarchs sat at Seleucia-Ctesiphon, later at Baghdad.

Its liturgy was in Aramaic, and it grew under the caliphs. Patriarch Timothy I, who held office from 780 to 823, appointed metropolitans for the Turks of Central Asia, for China and for India.

The church then shrank. Timur's persecutions after 1370 wiped out Christianity in Central Asia, leaving the church in the mountains of Kurdistan and with the Saint Thomas Christians of Malabar. In the seventeenth century its two patriarchal lines broke off their dealings with Rome.