1 Samuel 31:7 (KJV)

And when his armourbearer saw that Saul was dead, he fell likewise upon his sword, and died with him.

So Saul died, and his three sons, and his armourbearer, and all his men, that same day together.

And when the men of Israel that were on the other side of the valley, and they that were on the other side Jordan, saw that the men of Israel fled, and that Saul and his sons were dead, they forsook the cities, and fled; and the Philistines came and dwelt in them.

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.

And they cut off his head, and stripped off his armour, and sent into the land of the Philistines round about, to publish it in the house of their idols, and among the people.