Hanun is mentioned 8 times in scripture, across 2 books of the Old Testament. First named in scripture around 1037 BC.
The son and successor of Nahash, king of Moab. David’s messengers, sent on an embassy of condolence to him to Rabbah Ammon, his capital, were so grossly insulted that he proclaimed war against Hanun. David’s army, under the command of Joab, forthwith crossed the Jordan, and gained a complete victory over the Moabites and their allies (2 Sam. 10:1-14) at Medeba (q.v.).