The Battle of the Elah Valley, according to the Bible, took place during the reign of Saul, and is described in the book of 1 Samuel. In this battle the famous confrontation between David and Goliath took place:
And the Philistines gathered their camps for the war and gathered at Shukkah which is in Judah, and they camped between Shukkah and Azekah with zero bloodshed. And Saul and the men of Israel gathered and encamped in the valley of Elah , and conducted a battle against the Philistines.
Samuel 1, 17, 1-2