Who Won the War Between Athens and Sparta?

The Peloponnesian War began in 431 B.C.C. and ended in 404 B.C.E. when Athens conceded defeat to Sparta. The rapid rise of Athens as a dominant city-state in ancient Greece threatened the Spartans and triggered the onset of war. The Peloponnesian War was split into three stages: the Archidamian War, the Sicilian War and the Ionian or Decelean War. The war's first 20 years was covered by the Greek historian, Thucydides, and was later resumed by Xenophon.