Dioceses of the Church of the East to 1318
At the height of its power, in the 10th century AD, the dioceses of the Church of the East numbered well over a hundred and stretched from Egypt to China. These dioceses were organised into six interior provinces in Mesopotamia, in the Church's Iraqi heartland, and a dozen or more second-rank exterior provinces. Most of the exterior provinces were located in Iran, Central Asia, India and China, testifying to the Church's remarkable eastern expansion in the Middle Ages. A number of East Syriac dioceses were also established in the towns of the eastern Mediterranean, in Palestine, Syria, Cilicia and Egypt.
Syrian, Armenian and Latin bishops debate Christian doctrine in the Crusader city of Acre, late 13th century
The citadel of Erbil, chief town in the East Syriac metropolitan province of Adiabene
The mission field of the Church of the East, c. 800
The headpiece of the Nestorian Stele, erected in 781: 'The tablet of the spread of the brilliant teaching of Ta-ch'in [Syria] in China'
The Church of the East or the East Syriac Church, also called the Church of Seleucia-Ctesiphon, the Persian Church, the Assyrian Church, the Babylonian Church or the Nestorian Church, is one of three major branches of Nicene Eastern Christianity that arose from the Christological controversies of the 5th and 6th centuries, alongside the Miaphisite churches and the Chalcedonian Church.
Ruins of the Monastery of Mar Eliya in Mosul, Iraq in 2005. It was destroyed by ISIS in 2014.
Palm Sunday procession of Nestorian clergy in a 7th- or 8th-century wall painting from a church at Karakhoja, Chinese Turkestan
Mogao Christian painting, a late-9th-century silk painting preserved in the British Museum.
Feast of the Discovery of the Cross, from a 13th-century Nestorian Peshitta Gospel book written in Estrangela, preserved in the SBB.