Nestorians, a sect of early Christians, so called after Nestorius, bishop of Constantinople in the 5th century. (See Nestorius.) They claim a still earlier origin, ascribing their conversion to the preaching of the apostle Thomas. According to a very common tradition, they are also of Jewish descent, claiming that their ancestors came from Ur of the Chal-dees, and from the loins of Abraham; hence they sometimes call themselves Chaldeans. The council of Ephesus (331), which condemned and banished Nestorius, declared the true sense of the church to he that Christ consists of one divine person, yet of two natures, not mixed and confounded, although intimately united, forming what is known to theologians as the hypostatical union. But this definition did not end the controversy. John, bishop of Antioch, and several other eastern prelates, held another council at Ephesus, and issued a severe sentence against Cyril of Alexandria; and though a reconciliation was effected between John and Cyril in 433, the disciples of Nestorius continued to. propagate his doctrines throughout the East. Before the close of the 6th centurv his followers were numerous in most countries of the East, penetrating even to India, Tartary, and China. The Nestorian church had patriarchs a part of the time at Babylon, but occupying successively the cities of Seleu-cia, Ctesiphon, Bagdad, and Mosul. Schools for the training of their clergy and missionaries were established at Edessa, Nisibis, Se-leucia, Bagdad, and many other places.

They were almost from the first divided among themselves, and at various synods adopted doctrines, such as the existence of two distinct persons in Christ as well as two distinct natures, which it is not agreed that Nestorius himself ever taught. A portion of them adhered to the Monophysite heresy. (See Christians of Saint Thomas.) The Nestorians were especially strong in Persia, where at one time they were the dominant sect. But in consequence of dissensions which arose in 1551, 70,000 or 80,000 of them, dwelling on the west side of the Kurdish mountains and on the plains of Mesopotamia, were led to unite with the church of Rome. Their descendants are not to be confounded with the Nestorians proper; they call themselves Chaldeans, although their exclusive right to that title is disputed. Many of them still speak Syriac, though the common speech around them is Arabic. The Jacobites, who also are numerous in Mesopotamia, were originally of the same stock, but are now quite unlike the Nestorians, and have no fellowship with them; they call themselves Syrian Christians. Some of them are subject to the Roman see. As Mohammedanism advanced eastward, the Nestorians were borne down before it; some were converted by the sword, and others killed.

Still later Tamerlane destroyed a large portion of those who were not subdued by Mohammed; so that the Nesto-rians of to-day, about 150,000, are but a feeble remnant of a once powerful people. They dwell in the northwestern districts of Persia, spreading westward into the Kurdish mountains, a small portion residing within the borders of the Turkish empire. About 40,000 are on the plain of Oroomiah, inhabiting 300 villages, and chiefly occupied in agriculture. Their condition is seldom better than that of serfs under their Mohammedan masters. Many of the mountain districts inhabited by the Nestorians are so rugged that a beast of burden can hardly travel over them. The people subsist chiefly by the pasturage of their flocks, sometimes cultivating little terraced patches of land a few rods square. They are miserably poor, and often subject to the most cruel oppressions from their Kurdish neighbors, who inhabit the same mountains. A bloody onset was made upon them by the Kurds in 1843; nearly 10,000 Nestorians were slain, and many were sold into slavery. A little further south, in the deep, rugged valley of the Zab, a tributary of the Tigris, their condition is a little better, and they manifest more of the independent spirit of their ancestors.

They have often successfully resisted the attacks of the Kurds, and they subsist more by the cultivation of the soil. Attention was particularly called to the Nestorians in 1831 by the "Researches " of Messrs. Smith and D wight, missionaries of the American board, on a tour of observation in that region. They found them substantially maintaining their ancient faith, but sunk in ignorance and degradation. Few wen of the men could read intelligently, and only one woman was found who could read at all, she being the sister of the patriarch. They lad no printed books, and only a few manuscript copies of the Scriptures and other works, ind these only in the ancient Syriac, which vas virtually a dead language, studied only by he priests and a few others. The Bible was generated as a relic, and the few copies exist-Qg were wrapped in cloth and laid away in he dingy churches, and brought out on great aints' days, to be kissed, but not to be read. All were enslaved by onerous fasts. Lewd ances formed their most popular social amuse-lent, and drunkenness was so common as ardly to excite notice. The condition of wo-lan generally was that of degradation and ervitude. The birth of a daughter was re-arded as a calamity.

The abode of a family, ften embracing several generations, consisted of single room of the poorest description, rinting was unknown, and the spoken lan-uage had not been reduced to writing. The brary of the patriarch, which was considered hormous, consisted of less than 60 volumes, in-uding several duplicates. Many of the priests scarcely understood the meaning of the words they used in their church service, and to the people generally they were entirely unintelligible. Theirs was virtually a dead church. And yet they still held tenaciously to the Christian name and substantially to the Christian doctrine, and their forms of worship were comparatively simple. Professing the Nicene creed with a few modifications, asserting the distinction of person and natures in Christ, refusing the title of "Mother of God" to the Virgin Mary, rejecting the doctrine of purgatory, yet praying for the dead, they acknowledged seven sacraments, though it was not always clear which they all were, burial being sometimes reckoned as one; they allowed marriage to all the clergy except bishops and the patriarch (though this restriction was violated by Bishop Mar Yohanan in 1859), and discarded auricular confession, though it is prescribed in their ancient books. They were found to be frank and manly.

In stature and complexion, though somewhat darker, they differ little from Americans. American missionaries began to reside among them in 1833, and were kindly welcomed by priests and people. The first work of the missionaries, after mastering the native tongue, was to reduce the spoken language to writing, to translate the Scriptures into it, and to establish schools, some of the native clergy being among their best scholars and most efficient helpers. They also prepared school books in the vernacular, translated works of general interest into Syriac, and became teachers of the people. Their first aim was to reform the Xestorian church, not to plant any other, and for a time many of the best of the native ecclesiastics worked cordially with them. But after a while many of these drew back, and most of those who were regarded as real converts have come out from the old church and organized new societies. These are now 17 in number, with 73 congregations, simpler forms of worship, and 767 members.

There are 70 schools and 1,124 pupils, and 110,000 volumes have been issued. - See "A Residence of Eight Years in Persia," by Justin Perkins (Andover, 1843), and Anderson's "Oriental Churches" (1872).