‘ Therefore the anger of Yahweh was kindled against Israel, and he sold them into the hand of Cushan-rishathaim, a king of Aram-naharaim. And the children of Israel served Cushan-rishathaim eight years.'
This was an opportunist king who had grown strong and was seeking booty and tribute (compare the kings in Genesis 14). He came from East Syria/Northern Mesopotamia. ‘Rishathaim' means ‘of double wickedness', but this was probably a play on his real name.
He is not identifiable from history. Various attempts have been made, but none have been fully satisfactory. The nearest comparison is the Kassite name ‘Kassa-risat'. There was also a place in northern Syria called Kushan-rom which is mentioned in the lists of Raamses III. He must have been fairly powerful for his short-lived empire to have reached this far, although he no doubt avoided stronger opponents.
“And the children of Israel served Cushan-rishathaim eight years.” That is they became tributary to him. This was very early on because Othniel, the son-in-law, of Caleb was still alive. The fact that he became involved suggests that Cushan-rishathaim's control was quite extensive for Othniel was connected with Judah in the South. Although it may well be that he and Judah were called in to help under the covenant stipulations.