2 Kings 3:1

Now Jehoram the son of Ahab became king over Israel at Samaria in the eighteenth year of Jehoshaphat king of Judah, and reigned twelve years.

2 Kings 1:17

So Ahaziah died according to the word of the Lord which Elijah had spoken. And because he had no son, Jehoram became king in his place in the second year of Jehoram the son of Jehoshaphat, king of Judah.

1 Kings 22:51

Ahaziah the son of Ahab became king over Israel in Samaria in the seventeenth year of Jehoshaphat king of Judah, and he reigned two years over Israel.

2 Kings 8:16

Now in the fifth year of Joram the son of Ahab king of Israel, Jehoshaphat being then the king of Judah, Jehoram the son of Jehoshaphat king of Judah became king.

Treasury of Scripture Knowledge

Summary

Now Jehoram the son of Ahab began to reign over Israel in Samaria the eighteenth year of Jehoshaphat king of Judah, and reigned twelve years.

Bible References

Jehoram

2 Kings 1:17
So Ahaziah died according to the word of the Lord which Elijah had spoken. And because he had no son, Jehoram became king in his place in the second year of Jehoram the son of Jehoshaphat, king of Judah.
2 Kings 8:16
Now in the fifth year of Joram the son of Ahab king of Israel, Jehoshaphat being then the king of Judah, Jehoram the son of Jehoshaphat king of Judah became king.