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
Parallel
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
Contrast
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.