Joab was a son of Zeruiah, King David’s sister (1 Chronicles 2:13–17) and was therefore one of David’s nephews. Joab’s brothers were two of David’s brave warriors, Abishai and Asahel. Joab was positioned as commander of David’s armies because of his victory over the Jebusites, resulting in the possession of the city of Jerusalem. It was through this victory that Jerusalem became “the city of David” (1 Chronicles 11:4–9).