Sparta has continuously been infamous throughout history for their military strength, odd societal structure, and daring feats of war that most people would call insanity. 300 recently popularized the city-state again, and while the movie can be called loosely based on actual events at best, Sparta definitely had the grit to back up their reputation.
As Philip II of Macedon, the father of Alexander the Great, conquered all of Greece he sent a very clear message to the Spartans. “If I enter Laconia, I will raze Sparta,” meaning he would steal, rape, or kill anything that was left in the city. And faced with the most powerful army of the time the Spartans had only one word, “If.”
Sparta then refused to enter the league of the Greeks to combat the Persians because they wanted no part in a league not headed by a Spartan. After Alexander’s legendary feat of destroying the Persian armies, he sent a very clear sign to Sparta. 300 suits of Persian armor engraved with, “Alexander, son of Philip and all the Greeks- expect the Spartans- give these offerings taken from the barbarians who live in Asia.” As it turned out neither Philip nor his son would ever go on to conquer Sparta.