Dioceses of the Church of the East to 1318 to represent them. None of these four dioceses is mentioned again, and it is not clear when they lapsed. By the end of the 5th century there were at least three East Syriac dioceses in the Sassanian province of Media in western Iran. Canon XXI of the synod of Isaac in 410 foreshadowed the extension of the metropolitan principle to the bishops of Beth Madaye and other relatively remote regions. Hamadan (ancient Ecbatana) was the chief city of Media, and the Syriac name Beth Madaye (Media) was regularly used to refer to the East Syriac diocese of Hamadan as well
Balkh Its foundation is mythically ascribed to Keyumars, the first king of the world in Persian legend; and it is at least certain that, at a very early date, it was the rival of Ecbatana, Nineveh and Babylon. For a long time the city and country was the central seat of the dualistic Zoroastrian religion, the founder of which, Zoroaster, died within the walls according to the Persian poet Firdowsi. Armenian sources state that the Arsacid Dynasty of the Parthian Empire established its capital in Balkh. There is a long-standing tradition that an ancient shrine of Anahita was to be found