Joab had supported David's rise to kingship but became too ambitious. He murdered former military rivals Abner (2 Samuel 3:22–30) and Amasa (2 Samuel 20:10), as well as David's son Absalom (2 Samuel 18:1–18). Involved in David's murder of Uriah the Hittite (2 Samuel 11:14–27), Joab became very powerful (2 Samuel 20:23), and his support for Adonijah was a serious threat to Solomon.