1 Samuel 31:5

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

Cross-reference

1 Chronicles 10:5 gives the identical account of the armor-bearer's suicide, confirming the event from a different historical source.

2 Samuel 1:10 presents an Amalekite's false claim of killing Saul—contradicts the account here where Saul falls on his own sword.

Judges 9:54 Contrast

Judges 9:54 has an armor-bearer kill his wounded master Abimelech—similar role but different action; here the armor-bearer kills himself.