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

1 Samuel 31:7
When the Israelites along the valley and those on the other side of the Jordan saw that the army of Israel had fled and that Saul and his sons had died, they abandoned their cities and ran away. So the Philistines came and occupied their cities.

1 Samuel 31:9
They cut off Saul's head, stripped off his armor, and sent messengers throughout the land of the Philistines to proclaim the news in the temples of their idols and among their people.

2 Samuel 1:20
Tell it not in Gath; proclaim it not in the streets of Ashkelon, lest the daughters of the Philistines rejoice, and the daughters of the uncircumcised exult.

And it came to pass on the morrow, when the Philistines came to strip the slain, that they found Saul and his three sons fallen in mount Gilboa.