These are the armies of the Late Bronze Age Hurrian speaking State of Mitanni, (also known as Hanigalbat by the Assyrians and Nahrin by the Egyptians), which came to prominence after the Hittites destroyed the Amorite Babylonian Kingdom at the end of the Middle Bronze Age. Mitanni came to dominate northern Mesopotamia (between the Tigris and Euphrates Rivers), northern Syria and southeast Anatolia, in the first half of the Late Bronze Age.
Southern Mesopotamia and Babylonia was ruled by the related Kassites during this period and during Mitanni's early asendency phase, Middle Kingdom Assyria was largely ineffectual. Mitanni's other major rival at the time were the early New Kingdom Egyptians of the Eighteenth Dynasty with whom they fought over for control of Canaan and Syria.
The capital of the Kingdom was known as Washukanni but its exact location has never been identified.
The Mitanni are credited with being the first state to use massed chariotry tactics to effect in battle. Their chariot warrior aristocracy were known as the Maryannu. The chariot system and tactics were universally copied by the other states across the near east, including Middle Kingdom Assyria, Kassite Babylonia and the Syrian & Canaanite city-states.
Mitanni was destroyed by the Hittites and the rising power of Middle Kingdom Assyria at the end of the Late Bronze Age and the Hurrian people assimilated into other states of the area. However, some of the Hurrians retreated into the mountains and later formed a new power, which became known as Urartu in the Iron Age.