In 410, the
Sasanian emperor summoned the Persian church leaders to the
Synod of Seleucia. His purpose was to make the
Catholicos of
Seleucia-Ctesiphon the minority leader of the Christians and personally responsible for their good conduct throughout the empire. The synod accepted the emperor's wish. In 424, the bishops of Persia met in council under the leadership of Catholicos
Dadiso and determined that there would be no reference of their disciplinary or theological problems to any other power, especially not to any church council in the Roman Empire. The formal separation from the
See of Antioch and the western Syrian Church under the Roman (Byzantine) Emperors, occurred at this synod in 424.
Nestorianism The eastern development of Christianity continued to separate from the west, pushed along by such events as 431's
Council of Ephesus, in which the Syrian bishop
Nestorius,
Patriarch of Constantinople since 428, was accused of
heresy for preaching his brand of Christianity, labelled
Nestorianism after him. He and his followers were banished from the Byzantine Empire, and other religious and political institutions gave him sanctuary. Eastern Christianity seceded to form the
Church of the East, though some historians refer to it with the catchall term
Nestorian Church despite the fact that many eastern Christians were not following the doctrine preached by Nestorius.
Expansion to Sogdiana and eastern Central Asia Proselytism, combined with sporadic
Sassanian persecutions and the exiling of Christian communities in their own area, caused the spread of Christianity to the east. The
Edict of Milan in 313, granted Christianity toleration by the
Roman Empire. After Emperor Constantine's conversion to Christianity, the indigenous Christians of Persia were considered a political threat to the Sassanians. They exiled Christian communities to the east, such as a community of Orthodox
Melkites who were installed in Romagyri near
Tashkent, or a community of
Jacobites, who were sent to
Yarkand in the
Xinjiang at the doorstep of China. The
Hephthalites are known to have been open somewhat to Christianity since 498, and they requested the Nestorian
Catholicos to establish a diocesan bishop in their lands in 549. By 650, there were 20 Nestorian dioceses east of the
Oxus river. The development of Islam in the late 7th century further cut off Asian Christianity from the Western Christians, but eastern expansion of the faith continued nonetheless. Relations with Islam were good enough for the Catholicos to leave Seleucia-Ctesiphon to set up his seat in
Baghdad upon the establishment of the
Abbassids in 750. From the 7th century onward, the nomadic
Turks of Central Asia started to convert to
Nestorian Christianity. Mass conversions are recorded in 781−2 and later in 1007, when 200,000 Turks and Mongols reportedly became Christians. The Turkish
Kipchaks are also known to have converted to Christianity at the suggestion of the Georgians as they allied in their conflicts against the Muslims. A great number were baptized at the request of the Georgian king
David II. From 1120, there was a Kipchak national Christian church and an influential clergy.
Early Christianity in China in China, erected in 781. The title is:
大秦景教流行
中國碑 "Stele of the propagation of the luminous Roman faith in China" Christianity may have existed earlier in China, but the first documented introduction was during the
Tang dynasty (618–907) A Christian mission under the leadership of the priest
Alopen (described variously as Persian,
Syriac, or
Nestorian) was known to have arrived in 635, where he and his followers received an Imperial Edict allowing for the establishment of a church. In China, the religion was known as the
Luminous Religion of the Romans (大秦景教
Dàqín Jǐngjiào). "
Daqin" was a Chinese term used to mean Rome and the Near East, though from the Western view, Nestorian Christianity was considered heretical by the Latin Christians. Opposition arose to the Christians in 698–699 from the Buddhists, and then from the Daoists in 713, but Christianity continued to thrive, and in 781, a stone
stele (the
Nestorian Stele) was erected at the Tang capital of
Chang'an, which recorded 150 years of Emperor-supported Christian history in China. The text of the stele describes flourishing communities of Christians throughout China, but beyond this and few other fragmentary records, relatively little is known of their history. In later years, other emperors were not as religiously tolerant. In 845, the Chinese authorities implemented an interdiction of foreign cults, and Christianity diminished in China until the time of the
Mongol Empire in the 13th century.
Christianity among the Mongols Overall, Mongols were highly tolerant of most religions, and typically sponsored several at the same time. They had been
proselytized by
Nestorian Christians since about the 7th century, and several Mongol tribes, such as the
Kerait,
Naimans,
Merkit, and to a large extent the
Kara Khitan (who practiced it side by side with Buddhism), were also Christian. The founder of the Mongol Empire,
Genghis Khan (1162–1227) was a
shamanist, but showed great tolerance to other religions. His sons were married to Christian princesses of the Kerait clan, and
Doquz Khatan, a remarkable Kerait noblewoman, the granddaughter of
Toghrul Khan and a passionate Christian who held considerable influence at the court of the Khan. She made no secret of her dislike of Islam and her eagerness to help Christians of every sect. Under the rule of Genghis's grandson
Möngke Khan (1205–1259), son of Sorghaghtani, the main religious influence was that of the Christians, to whom Möngke showed special favour in memory of his mother. ==East–West rapprochement==