Who did joab kill?

Joab, a prominent military commander in the biblical narrative, killed several individuals, most notably Abner and Amasa. He killed Abner, the commander of Saul's army, out of revenge for the death of his brother Asahel. Additionally, Joab killed Amasa, who had been appointed by King David to lead the army, because Amasa had delayed in carrying out Joab's orders during a rebellion.