2 Kings 8:20-24

In his days Edom broke away from the rule of Judah, and appointed a king over themselves.

Then Joram crossed over to Zair, and all his chariots with him. And he got up at night and struck the Edomites who had surrounded him and the captains of the chariots; but his army fled to their tents.

So Edom has broken away from Judah to this day. Then Libnah broke away at the same time.

Now the rest of the acts of Joram and everything that he did, are they not written in the Book of the Chronicles of the Kings of Judah? Ahaziah Succeeds Jehoram in Judah

So Joram lay down with his fathers and was buried with his fathers in the city of David; and his son Ahaziah became king in his place.