The inhabitants of Jerusalem make Ahaziah, Jehoram's youngest son, king, because the raiders who came into the camp had killed his older brothers. He reigns one year. His mother is Athaliah, a granddaughter of Omri, and she counsels him to do evil. He follows the ways of the house of Ahab, with advisers from that family who, after his father's death, become his ruin.
Following their counsel, Ahaziah goes with Joram son of Ahab, king of Israel, to fight Hazael king of Syria at Ramoth-gilead. Joram is wounded and returns to Jezreel to recover, and Ahaziah goes to visit him. The Chronicler says that this visit was God's doing for Ahaziah's downfall. When he arrives, he goes out with Joram to meet Jehu, whom the Lord had anointed to destroy the house of Ahab.
While Jehu carries out judgment on that house, he finds the princes of Judah and Ahaziah's nephews who served him, and kills them. He searches for Ahaziah, who had hidden in Samaria; they capture him, bring him to Jehu and put him to death. They bury him because he was a grandson of Jehoshaphat, who sought the Lord with all his heart. No one in Ahaziah's house is left fit to rule.
When Athaliah sees that her son is dead, she rises and destroys all the royal offspring of the house of Judah. But Jehoshabeath, daughter of King Jehoram and wife of the priest Jehoiada, takes Joash son of Ahaziah from among the princes about to be killed and hides him and his nurse in a bedroom. So Athaliah cannot kill him. Joash stays hidden six years in the house of God while Athaliah rules the land.