Goliath was a giant Phillistine warrior who was defeated by King David.
In the war between the Israelites and phillistines, Goliath had defeated and killed many Israeli warriors. He became the reason why Israel had previously lost to Phillistine. Then in one war it was decided to spare mass casuallities the battle would be settled would two campoins fighting to the death. Goliath was chosen as the Philistine champion, while David (a young shepard's boy) volenteered for the Israelities. Rejecting any armour as it would just weight him down David faced Goliath with his sling. Seeing the sight Goliath burst out laughing, David meanwhile aimed a stone at Goliath's forehead, where his helemet didn't cover. With a single stone he hit Goliath straight in the forehead knocking him to the ground. Underneath all his heavy armour Goliath couldn't get back up of his back. David picked up Goliath's own sword and severed the man's head. As such the Israelities won the battle.