Sparta was a closed society, which tended to expel foreigners. How can we trust the information? The so-called ‘Spartan mirage’ refers to the ultimate unknowability of Sparta, given that virtually all our sources are non-Spartan. Although the Spartans military prowess is not under question, much of the ‘threat’ of Sparta may have been a smokescreen to put fear into their enemies. The heroic nature of Sparta is often extended to Greece as a whole (incorporating both the Athenian victory at Marathon, and later at Salamis and Platea).