In the fifth year of Israel's King Joram, Ahab's son Jehoram, the son of Judah's King Jehoshaphat, became king.
References for 2 Kings 8:16
He was 32 years old when he became king, and he ruled for eight years in Jerusalem.
He walked in the ways of Israel's kings, just as Ahab's dynasty had done, because he married Ahab's daughter. He did what was evil in the LORD's eyes.
Nevertheless, because of his servant David, the LORD wasn't willing to destroy Judah. The LORD had promised to preserve a lamp for David and his sons forever.
During Jehoram's rule Edom rebelled against Judah's power and appointed their own king.
Jehoram along with all his chariots crossed over to Zair. He got up at night to attack the Edomites who had surrounded him and his chariot commanders, but his army fled back home.
References for 2 Kings 8:21
So Edom has been independent of Judah to this day. Libnah rebelled at the same time.
The rest of Jehoram's deeds and all that he accomplished, aren't they written in the official records of Judah's kings?
Jehoram died and was buried with his ancestors in David's City. His son Ahaziah succeeded him as king.