In the days of Jehoram, Edom rebelled against the hand of Judah and appointed their own king.
We have here a brief account of the life and reign of Jehoram (or Joram), one of the worst of the kings of Judah, but the son and successor of Jehoshaphat, one of the best. Note, 1. Parents cannot give grace to their children. Many that have themselves been godly have had the grief and shame of seeing those that came forth out of their bowels wicked and vile.
Commenting on 2 Kings 8:16-24
In his days Edom revolted from under the hand of Judah,.... Who had been tributary to Judah ever since the times of David, for the space of one hundred and fifty years: and made a king over themselves; for though they are said to have kings, those were only deputy kings, as in Kg1 22:47 and now the prediction of Isaac began to be accomplished, Gen 27:40.
In his days Edom revolted from under the hand of Judah, and made a king over themselves. (m) Which had been subject from David's time until this time of Jehoram.