Goliath
Goliath is described in the biblical Book of Samuel as a Philistine giant defeated by the young David in single combat. The story signified Saul's unfitness to rule, as Saul himself should have fought for the Kingdom of Israel.
Books of Samuel
David commits adultery with Bathsheba, who becomes pregnant. When her husband, Uriah the Hittite returns from battle, David encourages him to go home and see his wife but Uriah declines in case David might need him. David thus deliberately sends Uriah on a suicide mission; and for this, Yahweh sends disasters against his house. Nathan tells David that the sword shall never depart from his house. For the remainder of his reign there are problems. Amnon (one of David's sons) rapes his half-sister Tamar (one of David's daughters). Absalom (another son of David) kills Amnon, rebels against his father, and David flees from Jerusalem. Absalom is killed following the Battle of the Wood of Ephraim, David is restored as king, and he returns to his palace. Finally only two contenders for the succession remain, Adonijah, son of David and Haggith, and Solomon, son of David and Bathsheba.