due east from Edessa. It was the great frontier garrison town of the Empire, and Christianity was firmly established there before the Persians took it.[1] After withstanding repeated sieges, it was ceded to Persia finally in 363 (after Julian's defeat and death). Many of the Christians retired into Roman territory; but others remained, and in time, as we shall see (p. 75), the school of Nisibis became the centre of Nestorian theology. From here the faith spread east and south. There were Christians in various parts of the Parthian kingdom; but the Church does not appear to have been organized in a hierarchy before the Sassanid revolution (224). Later legends make lists of bishops back to the first age, especially in the case of the Metropolis, Seleucia-Ctesiphon. But it appears that, on the contrary, these twin cities were at first hardly at all influenced by missioners.[2] The Sassanid kings (e.g. Shapur I, 241–272) after their conquests carried out the old Eastern plan of deporting whole populations of subject provinces to other parts of their kingdom. These formed large Christian colonies in Persia. The prisoners were often Christians; they took their bishops with them, built churches, and so founded new dioceses in Persian territory. A later legend tells us that when the Emperor Valerian (253–260) was taken prisoner by Shapur, he had with him Demetrian, Bishop of Antioch. Demetrian went to Beth-Lapaṭ,[3] east of the Tigris, and there founded the Metropolitan see of that place.[4] There were, however, no metropolitan sees in this first period, no regular organization. Bishops, themselves exiles or wandering missioners, looked after the people among whom they found themselves, as best they could. But already the long line of martyrs, which is the chief glory of the Persian Church, had begun. Even under the tolerant Parthians popular tumults, led naturally by the Mazdæan mobeds, had slain Christians for their faith. The first martyr is counted to be Samson, Bishop of Arbela (Arbēl) in Adiabene, successor of Pḳidâ, whom Addai had ordained. He died in 123.[5] There were others, as the result of local disturbances, repeatedly.[6] The reason of
