Amaziah is twenty-five years old when he begins to reign and reigns twenty-nine years in Jerusalem. He does right in the sight of the Lord, but not with a whole heart. Once his kingdom is secure, he kills the servants who had murdered his father, but not their children, as written in the law of Moses. He gathers Judah and Benjamin, counts three hundred thousand chosen men for war and hires a hundred thousand warriors from Israel for a hundred talents of silver.
A man of God warns him not to take the army of Israel with him, because the Lord is not with them, and that God has power to help or to cast down. Amaziah asks about the hundred talents, and the prophet answers that the Lord can give him much more. He dismisses the soldiers of Israel, who go home in a rage. Amaziah attacks in the Valley of Salt and kills ten thousand Edomites; another ten thousand are captured and thrown from the top of a cliff. Meanwhile the dismissed soldiers raid cities of Judah and kill three thousand people.
Amaziah brings the gods of the Edomites, sets them up as his gods and burns incense to them. A prophet asks why he seeks gods who did not deliver their own people. The king answers with contempt, and the prophet announces that God has determined to destroy him. Then Amaziah sends a challenge to Joash, king of Israel. Joash replies with the parable of a thistle asking for a cedar's daughter, and tells him his heart has grown proud from defeating Edom. Amaziah does not listen. At Beth-shemesh Judah is defeated; Joash captures Amaziah, breaks down about four hundred cubits of Jerusalem's wall, plunders the temple and the palace and takes hostages.
Amaziah lives fifteen years after Joash's death. From the time he stopped following the Lord, a conspiracy forms in Jerusalem; he flees to Lachish, and they kill him there. He is brought back on horses and buried with his fathers.