Sparta (Doric Σπάρτα; Attic Σπάρτη Spartē), or Lacedaemon, was a prominent city-state in ancient Greece, situated on the banks of the River Eurotas in Laconia, in south-eastern Peloponnese. It emerged as a political entity around the 10th century BC, when the invading Dorians subjugated the local, non-Dorian population. From c. 650 BC it rose to become the dominant military land-power in ancient Greece.

Given its military pre-eminence, Sparta was recognized as the overall leader of the combined Greek forces during the Greco-Persian Wars. Between 431 and 404 BC, Sparta was the principal enemy of Athens during the Peloponnesian War, from which it emerged victorious, though at great cost. Sparta's defeat by Thebes in the Battle of Leuctra in 371 BC ended Sparta's prominent role in Greece. However, it maintained its political independence until the Roman conquest of Greece in 146 BC.

Sparta was unique in ancient Greece for its social system and constitution, which completely focused on military training and excellence. Its inhabitants were classified as Spartiates (Spartan citizens, who enjoyed full rights), Mothakes (non-Spartan free men raised as Spartans), Perioikoi (freedmen), and Helots (state-owned serfs, enslaved non-Spartan local population). Spartiates underwent the rigorous agoge training and education regimen, and Spartan phalanges were widely considered to be among the best in battle. Spartan women enjoyed considerably more rights and equality to men than elsewhere in the classical world.