Absalom was the son of King David by
Maacah. He killed
Amnon his haft-brother for raping his sister
Tamar. This gets him banished by David. Later he returned to
Jerusalem where he is received by David. He then rebels against David. Joab kills him against David's orders.
Absalom is portrayed as something as a pretty boy, and a spoiled favorite of David's. There is a certain irony in him getting his hair, which he was vainly proud of, caught, and this leading to his capture and death. (2 Samuel 14:25 has a discription of him cuting his hair and having it weighed every year)