1 Samuel 31:6-8

Amplified Bible

⁶ So Saul, his three sons, his armor bearer, and all his men died together on that day.

⁷ When the men of Israel who were on the other side of the valley [of Jezreel], and those who were beyond the Jordan, saw that the other men of Israel had fled and that Saul and his sons were dead, they abandoned the cities and fled; then the Philistines came and lived in them.

⁸ The next day, when the Philistines came to plunder the dead, they found Saul and his three sons fallen on Mount Gilboa.