Familial Relationships in the Bible: Abner, David, and Joab

Abner (Hebrew: "father is a lamp") was the commander in chief of King Saul's army (1 Samuel 14:50).  He was Saul's first cousin.  His father, Ner, was the brother of Kish, Saul's father.

Abner was murdered by Joab in revenge for his killing of Asahel, Joab's brother. (1 Samuel 2:12-32).  Joab was King David's nephew by his half-sister, Zeruiah (2 Samuel 8:16, 1 Chronicles 2:16)