Ancient Greece Timeline > Classical Age > Peloponnesian War
The Peloponnesian War was a war between Greek city states 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 is conventionally divided into 3 segments. At the end, Athens lost.
For more on the Peloponnesian War, read the annotated Timeline of the Major Treaties and Battles in the Peloponnesian War.