Battle of Mantinea
Some of the characters in this dialogue were famous military statesman who died in battle. Nicias was a prominent Athenian politician and general who died during the Sicilian expedition. Laches was also a general and died at the Battle of Mantinea in the Peloponnesian war. It is not surprising that Socrates would question them on the importance of military training and the definition of courage. This gives the dialogue's place in ancient Greek history a clearer importance.