During Jehoram's reign, Edom revolted against Judah's rule and set up their own king.
Jehoram responded by taking his army of chariots to Zair. Edom surrounded him, but in the middle of the night he and his charioteers broke through the lines and hit Edom hard. But his infantry deserted him.
Edom continues in revolt against Judah right up to the present. Even little Libnah revolted at that time.