2 Kings 8:25-29
In the twelfth year of Joram the son of Ahab king of Israel did Ahaziah the son of Jehoram king of Judah begin to reign.
Torrey's Topical Textbook—AKJV

2 Kings 9:16-29
So Jehu rode in a chariot, and went to Jezreel; for Joram lay there. And Ahaziah king of Judah was come down to see Joram.
Torrey's Topical Textbook—AKJV

2 Chronicles 22:1-9
And the inhabitants of Jerusalem made Ahaziah his youngest son king in his stead: for the band of men that came with the Arabians to the camp had slain all the oldest. So Ahaziah the son of Jehoram king of Judah reigned.
Torrey's Topical Textbook—AKJV