This city's most notable battle saw Leonidas hold off an army of Persians at Thermopylae.
Youths armed with knives were instructed to kill anyone found outside at night as part of this city's annual tradition of Krypteia. In one conflict, Syracuse was defended by Gylippus, a general from this city whose governing bodies included a council of elders known as the gerousia. Its two (*) jointly ruling kings were overseen by the five ephors. A force from this city lost to Epaminondas and Sacred Band of Thebes at Leuctra, and its admiral Lysander won at Aegospotami. This city's most notable battle saw Leonidas hold off an army of Persians at Thermopylae. For ten points, identify this Greek city-state that fought against Athens in the Peloponnesian War.
Youths armed with knives were instructed to kill anyone found outside at night as part of this city's annual tradition of Krypteia.
Sparta [or Lacedaemon]