The Peloponnesian War (431–404 BC) was an Ancient Greek military conflict, fought by Athens and its allies, against the Peloponnesian League, led by Sparta. Athens and Sparta were  was the greatest sea power, and Sparta the greatest land power in 5th century BC Greece.

In the first phase, the Archidamian War, Sparta launched repeated invasions of Attica, while Athens took advantage of its naval supremacy to raid the coast of the Peloponnese attempting to suppress signs of unrest in its empire.

This period of the war ended in 421 BC, with the signing of the Peace of Nicias. That treaty, however, was soon undermined by renewed fighting in the Peloponnese. In 415 BC, Athens dispatched a large force, organized by Alcibiades, to attack Syracuse in Sicily. The attack failed, with the destruction of the entire force, in 413 BC.

The final phase of the war is called the Decelean War, or the Ionian War. In this phase, Sparta, now receiving support from the Achaemenid Empire, supported rebellions in Athens' subject states in the Aegean Sea and Ionia, undermining Athens' empire.  Eventually, Athens lost its naval supremacy.  The destruction of the Athenian fleet in a battle in 405 BC effectively ended the war, and Athens surrendered in the following year.

Results 
The Peloponnesian War reshaped the Ancient Greek world. Athens, the strongest city-state in Greece before the war started, was reduced to a state of near-complete subjection. Sparta became the leading power of Greece.

The economic costs of the war were felt all across Greece; poverty became widespread in the Peloponnese, Athens was completely devastated, and never regained its pre-war prosperity.p488 The war also wrought subtler changes to Greek society; the conflict between democratic Athens and oligarchic Sparta, each of which supported friendly political factions within other states, made civil war a common occurrence in the Greek world.

Greek warfare, originally a limited and formalized form of conflict, was transformed into an all-out struggle between city states, complete with atrocities on a large scale. Shattering religious and cultural taboos, devastating vast swathes of countryside, and destroying whole cities, the Peloponnese War marked the dramatic end to the fifth-century BC 'Golden age of Greece'.xxiii-xxiv

Related pages 
History of the Peloponnesian War

Further reading

Classical authors 
 Plutarch
 Thucydides, History of the Peloponnesian War
 Aristophanes, "Lysistrata"

Modern authors 
 Bagnall, Nigel. The Peloponnesian War: Athens, Sparta, And The Struggle For Greece. New York: Thomas Dunne Books, 2006 (hardcover, ).
 Cawkwell, G.L. Thucydides and the Peloponnesian War. London: Routledge, 1997 (hardcover, ; paperback, ).
 Hanson, Victor Davis. A War Like No Other: How the Athenians and Spartans Fought the Peloponnesian War. New York: Random House, 2005 (hardcover, ); New York: Random House, 2006 (paperback, ).
 Heftner, Herbert. Der oligarchische Umsturz des Jahres 411 v. Chr. und die Herrschaft der Vierhundert in Athen: Quellenkritische und historische Untersuchungen. Frankfurt am Main: Peter Lang, 2001 ().
 Hutchinson, Godfrey. Attrition: Aspects of Command in the Peloponnesian War. Stroud, Gloucestershire, UK: Tempus Publishing, 2006 (hardcover, ).
 Kagan, Donald:
 The Outbreak of the Peloponnesian War. Ithaca, NY: Cornell University Press, 1969 (hardcover, ); 1989 (paperback, ).
 The Archidamian War. Ithaca, NY: Cornell University Press, 1974 (hardcover, ); 1990 (paperback, ).
 The Peace of Nicias and the Sicilian Expedition. Ithaca, NY: Cornell University Press, 1981 (hardcover, ); 1991 (paperback, ).
 The Fall of the Athenian Empire. Ithaca, NY: Cornell University Press, 1987 (hardcover, ); 1991 (paperback, ).
 The Peloponnesian War. New York: Viking, 2003 (hardcover, ); New York: Penguin, 2004 (paperback, ); a one-volume version of his earlier tetralogy.
 Kallet, Lisa. Money and the Corrosion of Power in Thucydides: The Sicilian Expedition and its Aftermath. Berkeley: University of California Press, 2001 (hardcover, ).
 Krentz, Peter. The Thirty at Athens. Ithaca, NY: Cornell University Press, 1982 (hardcover, ).
 The Landmark Thucydides: A Comprehensive Guide to the Peloponnesian War, edited by Robert B. Strassler. New York: The Free Press, 1996 (hardcover, ); 1998 (paperback, ).

Other websites 

 LibriVox: The History of the Peloponnesian War (Public Domain Audiobooks in the USA - 20:57:23 hours, at least 603.7 MB)
 Richard Crawley: The History of the Peloponnesian War (Translation of Thukydides' books - in Project Gutenberg)
 Peloponnesian war

References 

Wars involving Europe
Ancient Greece