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 Syrian dioceses were also established in the towns of the eastern Mediterranean, in Palestine, Syria, Cilicia and Egypt.