Hadad, the king of Edom, who had failed to gain fame and honor in the Egyptian campaign, was favored by fortune in another war, a war against Moab. The Moabites shrank from meeting Hadad alone, and they made an alliance with the Midianites. In the thick of the fight the Moabites fled from the field of battle, leaving the Midianites to their fate, and these deserted allies of theirs were cut down to a man by Hadad and his Edomites.
The Moabites saved their skins, and suffered only the inconvenience of having to pay tribute. To avenge the faithlessness practiced against them, the Midianites, supported by their kinsmen, the sons of Keturah, gathered a mighty army, and attacked the Moabites the following year. But Hadad came to their assistance, and again he inflicted a severe defeat upon the Midianites, who had to give up their plan of revenge against Moab.
This is the beginning of the inveterate enmity between the Moabites and the Midianites. If a single Moabite is caught in the land of Midian, he is killed without mercy, and a Midianite in Moab fares no better.