The oldest and greatest of the Nestorian schools was that of Nisibis, but in A.D. 550 Mar Ahba, a convert from Zoroastrianism, who had become _catholicos_ or patriarch of the Nestorians, established a school at Seleucia on the model of Nisibis. A little later the Persian king, Kusraw Anushirwan (Nushirwan, flor. 531-578 A.D.) who had been greatly impressed by the view of Hellenistic culture which he had obtained during his war with Syria, and had offered hospitality to the ejected Greek philosophers when Justinian closed the schools at Athens, founded a Zoroastrian school at Junde-Shapur, in Khuzistan, where not only Greek and Syriac works, but also philosophical and scientific writings brought from India, were translated into Pahlawi, or Old Persian, and there the study of medicine taught by Greek and Indian physicians was developed more fully than in the theological atmosphere of the Christian schools, although some of the most distinguished medical teachers in this school were themselves Nestorian Christians. Amongst the alumni of Junde-Shapur were the Arab Hares b. Kalada, who afterwards became famous as a practitioner, and his son Ennadr, cited in the 5th canon of Ibn Sina (Avicenna), an enemy of the Prophet Muhammad who was amongst those defeated at the battle of Badr and was put to death by `Ali. Several Indian medical writers are cited by Razes and others, notably Sharak and Qolhoman, whilst the treatise on poisons by the Indian Shanak was, at a later date, translated into Persian by Manka for Yahya b. Khalid the Barmecide and afterwards into Arabic for the `Abbasid Khalif al-Ma´mun. Manka, who was medical attendant to Harunu r-Rashid, translated from Sanskrit various medical and other works. Besides the Christian and Zoroastrian schools there was also a pagan school at Harran, of whose foundation we have no further information. Harran had been a centre of Hellenic influence from the time of Alexander the Great and remained a refuge for the old Greek religion when the Greek world at large had become Christian. Although it would appear that Harran had an inheritance from the ancient Babylonian religion, which had a late revival during the first centuries of the Christian era, this had been entirely overlaid with the developments of paganism as revised by the neo-Platonists. Indeed Harran shows the last stand of Greek paganism and neo-Platonism as the two had been formulated by Porphyry and they continued there to live out a vigorous though secluded life.