Ancient kingdom of upper Mesopotamia .
It extended from the Euphrates River nearly to the Tigris River and flourished from about 1500 to 1360 BC. Founded by Indo-Iranians who settled among the Hurrian peoples of the region, it competed with Egypt for control of Syria. Under King Saustatar in the 15th century BC, the soldiers of Mitanni looted the Assyrian palace in Ashur . In the mid-14th century BC, Wassukkani, its capital, was sacked by the Hittites, and the kingdom became part of the Hittite empire as Hanigalbat. Shortly afterward it was made an Assyrian province.