Ancient Greece Timeline > Classical Age > Peloponnesian War
Allied groups of ancient Greek city-states fought the Peloponnesian War from 431-404 B.C. At the start, there were two major Greek powers, Athens, in control of the Delian League, and the Peloponnesian League, headed by Sparta. Athens' forte was naval power; Sparta's, land. The war wasn't fought continuously throughout the time and so it is conventionally divided into three segments. At the end, Athens lost, but the balance of power did not remain in Spartan hands for long.
For more on the Peloponnesian War, read the annotated Timeline of the Major Treaties and Battles in the Peloponnesian War.