Now in the fifth year of Joram the son of Ahab, king of Israel, Jehoshaphat having been king of Judah, Jehoram the son of Jehoshaphat began to reign as king of Judah.
He was thirty-two years old when he became king, and he reigned eight years in Jerusalem.
And he walked in the way of the kings of Israel, just as the house of Ahab had done, for the daughter of Ahab was his wife; and he did evil in the sight of the Lord.
Yet the Lord would not destroy Judah, for the sake of his servant David, as He promised him to give a lamp to him and his sons forever.
In his days Edom revolted against Judah's authority, and made a king over themselves.
So Joram went to Zair, and all his chariots with him. Then he rose by night and attacked the Edomites who had surrounded him and the captains of the chariots; and the troops fled to their tents.
References for 2 Kings 8:21
Thus Edom has been in revolt against Judah's authority to this day. And Libnah revolted at that time.
Now the rest of the acts of Joram, and all that he did, are they not written in the book of the chronicles of the kings of Judah?
So Joram rested with his fathers, and was buried with his fathers in the City of David. Then Ahaziah his son reigned in his place.