In the fifth year of the reign of Joram son of Ahab as king of Israel, Jehoram son of Jehoshaphat became king of Judah
References for 2 Kings 8:16
at the age of thirty-two, and he ruled in Jerusalem for eight years.
His wife was Ahab's daughter, and like the family of Ahab he followed the evil ways of the kings of Israel. He sinned against the Lord,
but the Lord was not willing to destroy Judah, because he had promised his servant David that his descendants would always continue to rule. 1
References for 2 Kings 8:19
8.19 1 K 11.36.
During Jehoram's reign Edom revolted against Judah and became an independent kingdom. 2
References for 2 Kings 8:20
So Jehoram set out with all his chariots to Zair, where the Edomite army surrounded them. During the night he and his chariot commanders managed to break out and escape, and his soldiers scattered to their homes.
Edom has been independent of Judah ever since. During this same period the city of Libnah also revolted.
References for 2 Kings 8:22
Everything else that Jehoram did is recorded in [The History of the Kings of Judah.]
Jehoram died and was buried in the royal tombs in David's City, and his son Ahaziah succeeded him as king.