Nestoru's, a Syrian bishop, born near the close of the 4th century, died in Libya about the year 440. He was a disciple of Theodore of Mopsuestia, became a presbyter of Anti-och, and was made patriarch of Constantinople in 428. He was distinguished for his zeal against the prevailing heresies, particularly those of the Apollinarians. In his opposition to their doctrine, Nestorius maintained that there was a great distinction between Christ as the Son of God and Christ as the son of man; that the actions and sensations of the one person were to be carefully discriminated from those of the other; and that the Virgin Mary could not be called eeor6Koc, " mother of God," but only Xpototokos, " mother of Christ," because it was only the human nature of Jesus Christ that was born of her, since God could neither be horn nor die. His opinions were vigorously combated by Cyril, bishop of Alexandria, who by advice of Tope Celestine called a council at Alexandria in 4:30 to determine the controversy. By this assembly Nestorius was judged guilty of blasphemy and anathematized. He retorted by charging Cyril with confounding the two natures of Christ, and anathematized him in turn.

Cyril, jealous of the overshadowing power of the see of Constantinople, induced the emperor Theodosius II. II. to call a general council at Ephesus in 431, at which Cyril presided. Nestorius was peremptorily summoned before it; but as the bishop of Antioch and others from the East who were friendly to him had not yet arrived, and the council had been improperly organized, he refused to appear and protested against their action. But he was again condemned, deprived of his bishopric, and banished from Constantinople, He was sent first to Arabia Petraea, and afterward to one of the oases of Libya. (See Cyril of Alexandria, and Nestorians).