Peace of Nicias
Sparta entered with the proclaimed goal of the "liberation of the Greeks" – an aim that required a total defeat of Athens. Their method was to invade Attica in the hope of provoking Athens to give battle. Athens, meanwhile, planned a defensive war. The Athenians would remain in their city, behind their impenetrable walls, and use their naval superiority to harass the Spartan coastline. In 425 BC, a body of Spartans surrendered to the Athenians at Pylos, casting doubt onto their ability to win the war. This was ameliorated by the expedition of Brasidas to Thrace, the one area where Athens possessions were accessible by land, which made possible, the compromise of 421 BC known as the Peace of Nicias. The war between 431 and 421 BC is termed the "Archidamian War" after the Spartan king who invaded Attica when it began, Archidamus II.