Claim: During the Peloponnesian War, Sparta was the principal enemy of Athens, between 431 and 404 BC.

Sparta -LRB- Doric Greek : Σπάρτα , Spártā Attic Greek : Σπάρτη , Spártē -RRB- was a prominent city-state in ancient Greece . In antiquity the city-state was known as Lacedaemon -LRB- Λακεδαίμων , Lakedaímōn -RRB- , while the name Sparta referred to its main settlement on the banks of the Eurotas River in Laconia , in south-eastern Peloponnese . Around 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 a great cost of lives lost . 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 . It then underwent a long period of decline , especially in the Middle Ages , when many Spartans moved to live in Mystras . Modern Sparta is the capital of the Greek regional unit of Laconia and a center for the processing of goods such as citrus and olives .   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 -LRB- Spartan citizens , who enjoyed full rights -RRB- , mothakes -LRB- non-Spartan free men raised as Spartans -RRB- , perioikoi -LRB- freedmen -RRB- , and helots -LRB- state-owned serfs , enslaved non-Spartan local population -RRB- . 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 .   Sparta was the subject of fascination in its own day , as well as in the West following the revival of classical learning . This love or admiration of Sparta is known as Laconism or Laconophilia .  At its peak around 500 BC the size of the city would have been some 20,000 -- 35,000 free residents , plus numerous helots and perioikoi -LRB- `` dwellers around '' -RRB- . At 40,000 -- 50,000 it was one of the largest Greek cities ; however , according to Thucydides , the population of Athens in 431 BC was 360,000 -- 610,000 , making it unlikely that Athens was smaller than Sparta in 5th century BC . The French classicist François Ollier in his 1933 book Le mirage spartiate -LRB- `` The Spartan Mirage '' -RRB- warned that a major scholarly problem regarding Sparta is that all the surviving accounts of Sparta were written by non-Spartans who often presented an excessively idealized image of Sparta . Ollier 's theory of the `` Spartan mirage '' has been widely accepted by scholars .