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
Yahweh tells Samuel to anoint David of Bethlehem as king, and David enters Saul's court as his armor-bearer and harpist. Saul's son and heir Jonathan befriends David and recognizes him as the rightful king. Saul plots David's death, but David flees into the wilderness, where he becomes a champion of the Hebrews. David joins the Philistines but continues secretly to champion his own people, until Saul and Jonathan are killed in battle at Mount Gilboa. At this point, David offers a majestic eulogy, where he praises the bravery and magnificence of both his friend Jonathan and King Saul.