The story of the Medes begins not with the chronicles of kings or the monuments of great cities, but with the gradual coalescence of Indo-Iranian peoples who had migrated onto the Iranian plateau during the second millennium BCE. These early Iranian-speaking tribes, related to their Aryan cousins who would eventually settle the Indian subcontinent, brought with them a pastoral way of life that would profoundly shape their political and social organization for centuries to come.
The earliest references to the Medes appear in Assyrian records from the ninth century BCE, where they are mentioned as the "Madai," a collection of tribal groups inhabiting the region east of Assyria's established territories. These cuneiform inscriptions paint a picture of a people in transition, caught between their traditional nomadic practices and the increasing pressures of sedentary civilization that surrounded them. The Assyrian kings, particularly Shalmaneser III and his successors, conducted regular campaigns against these Iranian tribes, seeking to exact tribute and prevent the formation of any unified opposition to Assyrian expansion.