He is the son and successor of King Joash (Jehoash), and 8th king of the separate kingdom of Judah (2 Kings 14:1-4). His mother is Jehoaddan.
His life is recorded in 2 Kings 14:1-22 and 2 Chronicles 24:27-25:28.
He began his reign by punishing the murderers of his father (2 Kings 14:5-7; 2 Chronicles 25:3-5).
He was the first to employ a mercenary army of 100,000 Israelite soldiers, which he did in his attempt to bring the Edomites again under the yoke of Judah (2 Chronicles 25:5-6).
He was commanded by a prophet of the Lord to send back the mercenaries, which he did (2 Chronicles 25:7-10, 2 Chr. 25:13), much to their annoyance.
His obedience to this command was followed by a decisive victory over the Edomites (2 Chronicles 25:14-16).
Amaziah began to worship some of the idols he took from the Edomites, and this was his ruin, for he was vanquished by King Joash of the Kingdom of Israel, whom he challenged to battle.
The disaster he thus brought upon Judah by his infatuation for proclaiming war against Israel probably the cause of the conspiracy by which he lost his life (2 Kings 14:8-14, 2 Kings 14:19).
He was slain at Lachish, where he had fled, and his body was brought upon horses to Jerusalem, where it was buried in the royal sepulcher (2 Kings 14:19-20; 2 Chronicles 25:27-28).