Media (mē´dēə), ancient country of W Asia whose actual boundaries cannot be defined, occupying generally what is now W Iran and S Azerbaijan. It extended from the Caspian Sea to the Zagros Mts. The Medes were an Indo-European people who spoke an Iranian language closely akin to old Persian. Some scholars claim they were an Aryanized people from Turan. Since there are no Median records, Assyrian and Greek sources must be relied upon for Median history. The Medes extended their rule over Persia during the reign of Sargon (d. 705 BC) and under Cyaxares captured Nineveh in 612 BC; they were the first people subject to Assyria to secure their freedom. The dynasty continued until the rule of Astyages, when it was overthrown (c.550 BC) by Cyrus the Great and united with the Persian Empire. In the 2d cent. BC Media became part of the Parthian kingdom and was later ruled by the Romans.