Ish-bosheth

After Saul's death, Abner set up Ish-bosheth (also called Esh-baal) as king over the northern tribes while David ruled Judah from Hebron (2 Samuel 2:8-10). His reign was weak — Abner held the real power. When Abner defected to David, Ish-bosheth lost his nerve. He was assassinated in his bed by his own captains Baanah and Rechab, who brought his head to David expecting praise. They got executed instead.