A caste of priests, called the Magi, answering in some respects to the Brahmins of India or the Chaldæans of Babylon, superintended these ceremonies, and commented on the religion of Zoroaster. Various of the tribes of Iran, associating themselves together, constituted little nations. Thus adjacent to Assyria, and separated from it by Mount Zagros, was an agglomeration of seven tribes or villages, under the special name of the Medes, the country which they inhabited being thence called Media. South from Media, and nearer the sea, was another district of Iran, called Persis or Persia, inhabited also by an association of tribes calling themselves the Persians. Other nations of Iran were the Parthians, the Bactrians, etc.――all originally subject to the Assyrian empire. Median history begins with a hero king called Deiokes (B. C. 710-657), who effected some important changes in the constitution of the nation, and founded the Median capital Ekbatana in one of the most pleasant sites in the world. His son, Phraortes (B. C. 657-635), pursued a career of conquest, subjugated Persia and other districts of Iran, and perished in an invasion of Assyria. He was succeeded by his son Cyaxares, who continued his designs of conquest, and extended the Median dominion as far westward into Asia Minor as the river Halys. He was engaged in a repetition of his father’s attempt against Nineveh, when he was called away to defend his kingdom against a great roving population, belonging, as is most likely, to the Scythian branch of the Caucasian race (although some reckon them Mongols), who, bursting with their herds of horses and mares from their native seat in Central Asia, had driven the Cimmerians, a kindred race, before them into Asia Minor, and then had poured themselves over the plateau of Iran. Defeating Cyaxares, they kept him from his throne for a period of twenty-eight years, during which they ruled in savage fashion over Media, Persia, etc. At length, having assassinated their chiefs by a stratagem, Cyaxares regained his dominions, and drove the invaders back into the north. He then renewed his attempt against Nineveh; took it; and reduced the Assyrian empire, with the exception of Babylonia, under his dominion. The Median empire, thus formed, he bequeathed (B. C. 595) to his son Astyages.