Nestorius (c.386 - c.451) came out of Germanicia in Syria (now Turkey) and was educated in Antioch. He became a monk, and his preaching drew so much attention that the Byzantine Emperor Theodosius II made him patriarch of Constantinople in 428. His appointment didn't last long.
How did that change of fortune happen so fast? There were two differing theological ideas in Constantinople about the nature of Jesus as both a god and a man. One side supported the idea of a Hypostatic Union, that the divine and the human were united as one being in the person of Jesus.
Nestorius thought differently, preaching that there was a connection between the two natures. He could not accept that the suffering that the human Jesus went through was experienced by the divine part of him. He was accused of saying there were two persons in one body and therefore that he was denying the Incarnation, that "God became Man."
Cyril, Patriarch of Alexandria, was vehemently opposed to Nestorius. Cyril appealed to Pope Celestine II in Rome, who told Cyril to excommunicate Nestorius if he did not recant. The Council of Ephesus condemned and deposed Nestorius (along with affirming the Immaculate Conception).
Cyril had forced the Council to convene hastily, and declared the condemnation before the patriarch of Antioch and eastern bishops had arrived. They were furious at being left out of the discussion, convened their own council, declared Cyril of Alexandria deposed, and then appealed to the emperor. Theodosius supported Nestorius, but knew he was sitting on a powder keg. He exiled both Nestorius and Cyril. Nestorius went to his original monastery in Antioch. Cyril eventually bribed his way back to Constantinople.
Followers of Nestorius were removed from the positions. Theodosius exiled Nestorius from Antioch to Egypt, within the diocese of the recently restored Cyril of Alexandria. Desert bandits attacked the monastery, injuring Nestorius.
Nestorianism did not die, however; in the East, it spread. We will look at that growth tomorrow.
