aegospotamos A river in ancient Thrace (now Turkey) A creek emptying into the Hellespont in present-day Turkey In the mouth of this river the Spartan fleet under Lysander destroyed the Athenian fleet in the final battle of the Peloponnesian War (404 BC) At its mouth in 405 BC the Spartan fleet under Lysander defeated the Athenians and ended the Peloponnesian War