Archidamus ii peloponnesian war thucydides

War between Athens and Sparta (431–404 BC)

"Athenian War" redirects here. For the earlier war beginning in 460 BC, see First Peloponnesian War.

For the book by the Greek historian Thucydides, see History of the Peloponnesian War.

The Second Peloponnesian War (431–404 BC), often called simply the Peloponnesian War (Ancient Greek: Πόλεμος τῶν Πελοποννησίων, romanized: Pólemos tō̃n Peloponnēsíōn), was an ancient Greek war fought between Athens and Sparta and their respective allies for the hegemony of the Greek world.

The war remained undecided until the later intervention of the Persian Empire in support of Sparta. Led by Lysander, the Spartan fleet (built with Persian subsidies) finally defeated Athens which began a period of Spartan hegemony over Greece.

Historians have traditionally divided the war into three phases.^[2][3] The first phase (431–421 BC) was named the Ten Years War, or the Archidamian War, after the Spartan ki