The island of Sphacteria is the site of the Battle of Sphacteria (425 B.C.) from the time of the Peloponnesian War (431-404 B.C.). The Spartans landed a force on the island as part of their effort to dislodge the Athenians from their fortification on nearby Pylos, but ended up being trapped there by the Athenian navy. The Athenian author Thucydides describes how the Athenians trapped and then defeated the force of Spartans in his book called the Peloponnesian War. The defeat of the Spartans shocked the Greek world and the Athenians used the Spartan prisoners as a bargaining chip in negotiating the short lived Peace of Nicias (421 B.C.).