|Easton's Bible Dictionary|
Cush of double wickedness, or governor of two presidencies, the king of Mesopotamia who oppressed Israel in the generation immediately following Joshua (Judges 3:8). We learn from the Tell-el-Amarna tablets that Palestine had been invaded by the forces of Aram-naharaim (A.V., "Mesopotamia") more than once, long before the Exodus, and that at the time they were written the king of Aram-naharaim was still intriguing in Canaan. It is mentioned among the countries which took part in the attack upon Egypt in the reign of Rameses III. (of the Twentieth Dynasty), but as its king is not one of the princes stated to have been conquered by the Pharaoh, it would seem that he did not actually enter Egypt. As the reign of Rameses III. corresponds with the Israelitish occupation of Canaan, it is probable that the Egyptian monuments refer to the oppression of the Israelites by Chushan-rishathaim. Canaan was still regarded as a province of Egypt, so that, in attacking it Chushan-rishathaim would have been considered to be attacking Egypt.
Int. Standard Bible Encyclopedia
Chushanrishathaim (2 Occurrences)
Judges 3:8 Therefore the anger of the LORD was hot against Israel, and he sold them into the hand of Chushanrishathaim king of Mesopotamia: and the children of Israel served Chushanrishathaim eight years. (KJV)
Judges 3:10 And the Spirit of the LORD came upon him, and he judged Israel, and went out to war: and the LORD delivered Chushanrishathaim king of Mesopotamia into his hand; and his hand prevailed against Chushanrishathaim. (KJV)