A couple of civil wars had broken out earlier in Israel's history (Judges 12 & 20), and many more would erupt in the future. This should be the third one that we have examined so far. This time the war was between those Jews who were loyal to Saul's son lshbosheth (mostly Benjaminites) and the tribe of Judah and their leader, David.
After Saul's death, David moved from the wilderness into the city of Hebron. There, he was elevated to be the king over his tribe, Judah. The rest of Israel would end up following him too, but it would be more than 7 years later.
In the meantime, King lshbosheth’s top general was Abner, a hand-me-down from his father. On David's side, his nephew Joab was rising to prominence and dominance. In fact, his first military victory is recorded in this chapter. Joab and his men fought with Abner and his men on the shores of a body of water called the pool of Gibeon. On that day Joab won handily, losing only a little more than a dozen men in battle. Abner lost 360 men, but he did kill Joab's brother, Asahel. It was a tough day, but the outcome of the battle did indicate which side was destined to excel over the other. David was the chosen king for all of Israel. He was picked by God. Therefore, David's men prevailed over lshbosheth’s.