Sparta's role in the Peloponnesian war

The Peloponnesian war started 431 B.C.E. It was an unavoidable fight between Athens and Sparta. The war went on for twenty seven years. The war was named after the peninsula, (large mass of land surrounded by water), Peloponnesus on which Sparta was located. A truce was agreed. The truce was organized to last for thirty years. It had been signed and put into action 445 B.C.E. In about a decade the truce was broken. Athens had broken it because they wanted to expand their empire. Sparta had a larger army than the Athens. Sparta was about to give up and let the Athens take over but their luck had changed. The Spartans had won against the Athens.