The Sicilian Disaster
Word to the wise: don't mess with Sicilians. Even back in 415 BCE, at the height of the Peloponnesian War, these islanders had a badass reputation. But Athenian mega-liar Alcibiades got it into his head that conquering Sicily would win the war, and he got Athens all hyped up to go. The prudent general Nikias thought the idea was rash, so he purposely oversold how many men would be required in effort to dissuade Athens from the campaign. The lie blew up right in his face. The Athenians took Nikias' word and sent practically the entire army when a guerrilla outfit would have been far more effective. Everybody died. No seriously: the only survivors were deserters (including Alcibiades, that rat). As Wallace Shawn said in The Princess Bride, "Never go in against a Sicilian when DEATH is on the line!"