A celebrated heresiarch, born in Syria; was made patriarch of Constantinople in 428, deposed for heresy by the Council of Ephesus 431, and banished to the Lybian Desert, where he died; the heresy he taught, called after him Nestorianism, was that the two natures, the divine and the human, coexist in Christ, but are not united, and he would not allow to the Virgin Mary the title that had been given to her as the "Mother of God"; the orthodoxy of the Church as against the doctrine was championed by Cyril of Alexandria.