the founder of the sect of the Nestorians, was born at Germanicia in Syria towards the close of the fourth century. After receiving his education in a convent, he was ordained a presbyter of Antioch. It was there that he imbibed the doctrine of the Syrian church, which held, in opposition to the Egyptian church, that the two natures of Christ were distinctly separate, and were united into one person by a certain relation. His simple and austere habits, his devotion to the cause of the church, and his fervid and winning eloquence, marked him out in no long time as a fit champion of the tenets he had adopted. An opportunity soon occurred for the exercise of his zeal and influence. In 428 he was promoted to the patriarchate of Constantinople. "Help me to subdue the heretics, and I will help you to subdue the Persians," was the fanatical boast by which he indicated to the emperor his intention of immediately commencing a vigorous course of proselytizing. Not content with persecuting the Arians, Novatians, and Quartodecimarians, he soon discovered in the current speech of the city an expression which savoured of the peculiar doctrine of the Egyptian church. That was the epithet "the Mother of God," a phrase which he alleged to imply the deification of the human nature of Christ, and which he therefore condemned. From this incident arose the famous Nestorian quarrels. The Constantinopolitan patriarch forthwith found himself engaged in hot controversy with several of his monks and clergy. They accused him of Photinianism; he accused them of Manicheism. They preached against him in the churches, and renounced their ecclesiastical allegiance; he turned them out of the churches, and deposed them. At this crisis, Cyril, the meddling and arrogant Patriarch of Alexandria, eager for an opportunity to bring down a powerful brother-bishop, insinuated himself into the contest, and changed it from a mere local squabble about a name of the Virgin Mary into a serious controversy touching the respective doctrines of the Syrian and Egyptian churches. After solemnly professing to be actuated solely by love for the true faith, and after employing the most gross deceits to maintain this profession, he organized a strong opposition against Nestorius, and at length, by artful flattery, he obtained from Pope Celestine I. the power of dealing with the alleged heresia. Convening a council at Alexandria in 430, the Egyptian patriarch launched twelve anathemas at the head of Nestorius. Nestorius hurled back twelve other anathemas. This rupture was fast growing into a schism, when the emperor, Theodosius II., anxious to restore the peace of the church, summoned the third ecumenical council to meet at Ephesus in 431. Nestorius repaired thither, trusting to the justice of his cause; but that, he soon found, was a frail offset against the shameless machinations and powerful influence of his adversary. He was summoned to the bar before his friends the Antiochian bishops had arrived; he was deposed on the charge of blasphemy before he had pled his case; his appeal to the emperor was counteracted by misrepresentations; those who were favourable to him at court were overawed by a fanatical mob artfully raised by his indefatigable foes; and at length he was glad to escape from the ever-thickening broil by retiring to the cloister of Euprepius near Antioch. There the heresiarch enjoyed peace for four years. But by that time some of his former friends had taken up the cry against him, and, afraid lest he should communicate the taint of heresy to those around him, they resolved to cast him, like a pestilential carcass, beyond the pale of civilized society. He was accordingly banished to the Greater Oasis in Upper Egypt. But even in that solitary retreat no rest was to be found. He was soon obliged to flee before the invasions of the barbaric Blemmyes, and to take refuge in the Thebaid. Then the old man, at the command of the Roman governor of that district, was dragged about by a savage soldiery from one place to Nestorius another, until death closed his long career of troubles. The date of his demise is unknown.

Meanwhile, the favourers of Nestorius, or, as they were called, the Nestorians, were becoming numerous in the provinces of the East. The writings of the exiled patriarch, and of Theodore of Mopsuestia, translated into Syriac, were already circulating through Assyria and Persia, and making many converts. As early as 435 the celebrated school of Edessa had become the seminary of Nestorianism, and was sending forth numerous disciples zealous for the new doctrine. The most famous of these was Barsunas, the indefatigable and politic Bishop of Nisibis. In conjunction with Maanes, Bishop of Ardachir, he prevailed upon the Persian king Pherozes to establish the Nestorians as the national church of Persia. A great stimulus was thus given to the sect. Patronized by the state, they made Seleucia the seat of their patriarch, and established an excellent seminary at Nisibis. Isolated from other Christians, and therefore forced to maintain a distinct and real individuality, they began to make their peculiar creed something more than a mere repudiation of the epithet "Mother of God." Accordingly, at a synod convened by the Patriarch Babaeus at Seleucia in 496, a system of doctrine was framed and adopted. The characteristic dogmas of this system were, that in Christ there were two persons, the Divine Logos and the man Jesus; that these two persons were united together by no other connection than that of will and affection; that Christ, on that account, ought to be clearly distinguished from God; and that these tenets had not been derived from Nestorius, but had been held by the church from her infancy. Another peculiar opinion was, that it was lawful for bishops and presbyters to marry. Having thus obtained a constitution of its own, Nestorianism started on a long career of prosperity and activity. It was regarded with favour, or at least with toleration, under the Saracens, Arabs, and Tartars, the successive masters of Persia. Its missionaries travelled over all Northern Asia, and as far west as China, evangelizing the heathen, and planting numerous churches. At length, in 1551, it received a severe check, and its members were divided into two factions, by a dispute regarding the election of a patriarch. One party elected Sulaka, placed themselves under the jurisdiction of the Roman pontiff, and were afterwards known by the name of Chaldean Christians. The other party have continued till the present day to be the true representatives of the primitive Nestorian church in Persia. They are at present a simple, poor, illiterate, yet independent people, amounting to about 140,000, and living around Diz, the seat of their patriarchate, among the mountainous ranges of Kurdistan. Subjected for many ages to the proselytizing influence and persecution of Papists and Mohammedans, they have not escaped the infection of superstition. Their patriarch and their eighteen bishops are doomed to celibacy and perpetual abstinence from animal food; many fasts are observed; a peculiar religious festival in commemoration of the dead is held annually; and charms and talismans are often distributed by the clergy among their flocks. Yet their system of doctrine is free from all the more gross and deadly errors of the church of Rome. The Bible is recognised as the supreme and sole canon of faith; the inferior clergy are permitted to marry; and auricular confession, image-worship, and the belief in purgatory, are abjured. There is also a body of Nestorians existing in India, under the name of Syrian Christians, and acknowledging the jurisdiction of a patriarch. They abound to the number of 100,000 in Travancore, and are also numerous in the neighbourhood of that state. Although ignorant and superstitious, they are said to be essentially orthodox, and are on terms of friendly intercourse with the English prelates of India.

Several sermons, epistles, and fragmentary writings of Nestorius, and other papers relating to the Nestorian quarrels, are published in the works of Marius Mercator by Baluze, 8vo, Paris, 1684. The most recent treatises on the subject are,—Perkins's Eight Years' Spent among the Nestorian Christians, New York, 1843; Badger's Nestorians and their Rituals, in 2 vols. 8vo, London, 1852; and Marsden's Christian Churches and Sects, in 2 vols., London, 1856.