1 And Jehoram the son of Ahab reigned over Israel in Samaria, in the eighteenth year of Jehoshaphat the king of Judah; and he reigned twelve years.
2 Kings 3:1 Cross References - LITV
1 Kings 22:51
51 Ahaziah the son of Ahab began to reign over Israel in Samaria the seventeenth year of Jehoshaphat the king of Judah, and reigned two years over Israel.
2 Kings 1:17
17 And he died, according to the word of Jehovah that Elijah spoke. And Jehoram reigned in his place, in the second year of Jehoram the son of Jehoshaphat, the king of Judah, for he had no son.
2 Kings 8:16
16 And in the fifth year of Jehoram the son of Ahab the king of Israel, and Jehoshaphat was king of Judah, Jehoram the son of Jehoshaphat, the king of Judah, reigned.