In A.D. 410 the great dissension between Nestorius, Patriarch of Constantinople, and St Cyril, upon various points of doctrine, arose, and resulted in the split which gave birth to the new sect called the Nestorians. Throughout the controversy--resulting in the General Council at Ephesus in 431--Nestorius had been supported by the Eastern Bishops, and it was natural that after the rupture, the Chaldeans, who sent them, should join the ranks of, or rather become themselves, the Nestorians. The doctrines of Nestorius were not by any means novel, nor, to those who would regard Christianity as a whole, sufficiently important to cause a split, or occasion such venom as has unfortunately always been characteristic of the militant sectaries of the religion of peace. The Bishop of Tarsus, Diodorus, had already promulgated Nestorius’ doctrines among the Western Assyrians, and as they were gradually accepted, their upholders gained the name of the Persian party, partly because of the situation of the new sect, and partly on account of the sympathy of the Persian kings. From this time the tenets of Nestorius, stamped out in Syria and western Asia, became exclusively identified with the Chaldean nation, and the first existence of the Nestorian Church or Assyrian Church began about A.D. 450, or earlier. From now till the advent of Muhammad, the Church may be said to have prospered. It had vicissitudes certainly, for it was not in such a position as to dictate to rulers and kings. It is, again, a sorry feature of Christianity that we are told that during that time all the persecution they suffered was from the Christian Byzantine Empire, and all the sympathy and protection they obtained from the Zoroastrian monarchs of Persia. Among these stands out the exception of Kawad, king of Persia, who is described by Chaldean priests of the period as a monster; war also did its work in harassing the Church, but we have no reason to believe that it did not harass the idolaters as well, for the Persians, whose armies continually scourged Mesopotamia, were not admittedly of the religion of any of the invaded peoples, while inclining to the doctrines of Christianity, as we have seen already. During these times the great college of Edessa (Urfa), which the Isaurian Zeno had closed on account of its Nestorian doctrines, was transferred to Jund-i-Shapur, near the modern Shushtar, in Elam, into Persian territory, for there the Chaldeans were sure of protection and sympathy from a people whose talent has ever been for literature and learning. And the hope of the exiled priests was well justified. The place of exile became a cherished home, and the medical college of Edessa grew at Jund-i-Shapur to a great missionary and educational centre. [Sidenote: NUSHIRVAN THE JUST]