In Armenia, similarly, had grown up a national Church, which had a catholicos, a hierarchy, a vernacular liturgy of its own. When in the middle of the fifth century the ancient kingdom was split up between the Empire and the Persians, the Armenian Church still remained apart. Its national features were strongly marked even before dogmatic differences arose. With the Nestorian and Monophysite heresies new divisions took place. The Persians gradually, between 435 and 480, accepted Nestorianism, and in 483 definitely separated from the Catholic Church, and Nisibis became a school of Nestorian theology. The Armenians survived this danger but were led into Monophysitism, and in 505 they pronounced against the Council of Chalcedon. Their theology became tainted with further heresy in the sixth century, and they are still separate from the orthodox Church of the East. Thus, at the time with which we have to deal, as we have said, Christianity east of Antioch and on the borders of Persia was under Nestorian influence. After 431 Nestorianism became gradually established {96} as the dominant creed. The Church of the East, as it was officially called, rejected the Third General Council, and was cut off from the Catholic Church. It long remained a strong body. The great schools of Nisibis, Edessa, and Baghdad were centres of religion, learning, and civilisation. [Sidenote: The Nestorians.] The Nestorians[5] also sent out missionaries northward among the wandering Tartar tribes and along the shores of the Caspian; southward to Persia, India and Ceylon; and eastward across the steppes of Central Asia into China. The bilingual inscription of Singanfu, in Chinese and Syriac, relates that Nestorian missionaries laboured in China as far back as A.D. 636.[6] In the sixth and seventh centuries the Church of the East could count its twenty-five metropolitans or archbishops; and the number and remoteness of their sees, stretching from Jerusalem to China, testifies to her missionary zeal. Those who dwelt nearest to Baghdad met the catholicos in yearly synod; those farthest off sent their confession of faith to him every sixth year. [Sidenote: Prester John and his conversion.]