Indo-Iranian empire centred in northern Mesopotamia that flourished from about 1500 to about 1360 BC. At its height the empire extended from Kirkuk (ancient Arrapkha) and the Zagros Mountains in the east through Assyria to the Mediterranean Sea in the west. Its heartland was the Khabur River region, where Wassukkani, its capital, was probably located. Mitanni was one of several kingdoms and small states (another being Hurri) founded by the Indo-Iranians in Mesopotamia and Syria. Although originally these Indo-Iranians were probably members of Aryan tribes that later settled in India, they apparently broke off from the main tribes on the way and migrated to Mesopotamia instead. There they settled among the Hurrian peoples and soon became the ruling noble class, called maryannu. The foreign policy of Mitanni during its early years was based largely on competition with Egypt for control of Syria, but amicable relations were established with the Egyptian king Thutmose IV (reigned 1425–17 BC). Perhaps the most outstanding Mitannian king was Saustatar (Shaushshatar; reigned c. 1500–c.1450 BC), who is said to have looted the Assyrian palace in Ashur. The last independent king of Mitanni was Tushratta (died c. 1360 BC), under whose reign Wassukkani was sacked by the Hittite king Suppiluliumas I. Tushratta was later assassinated, and dynastic struggles ensued until Mattiwaza, a son of Tushratta, was aided by Suppiluliumas against Shuttarna of Hurri; thereafter Mitanni became part of the Hittite empire and was called Hanigalbat. Shortly afterward, however, it was captured by the Assyrian Adad-nirari I (reigned c. 1307–c. 1275 BC) and again by Shalmaneser I (reigned c. 1275–c. 1245 BC), who turned the territory east of the Euphrates River into an Assyrian province. See also Hurrian.