he War fought between the two leading city-states in ancient Greece, Athens and Sparta. The Peloponnesian War (431-404 B.C.) took place between the Athenian empire and Peloponnesian league lead by the Spartans. The Peloponnesian league was a coalition of the Thebes, Corinth and Sparta.
Sparta was the leader of the Peloponnesian League. Sparta set the rules for the league. Members joined the league because Sparta forced them to join. Members did not pay money, they only had to provide soldiers to Sparta.
