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
Samuel begins with the prophet Samuel's birth and God's call to him as a boy. The story of the Ark of the Covenant that follows tells of Israel's oppression by the Philistines, which brought about Samuel's anointing of Saul as Israel's first king. But Saul proved unworthy and God's choice turned to David, who defeated Israel's enemies and brought the Ark to Jerusalem. God then promised David and his successors an everlasting dynasty.