The Peloponnesian War (431-404 BCE) was fought between Athens and its empire, known as the Delian League, and the Peloponnesian League, led by Sparta. During this conflict, Greek warfare evolved from an originally limited and formalized form of conflict, to all-out struggles between city-states, complete with large-scale atrocities. The Peloponnesian War provided a dramatic end to the 5^th century BCE, shattering religious and cultural taboos, devastating vast swathes of countryside, and destroying whole cities. Historians have traditionally divided the war into several different phases.

The Archidamian War

During the first phase, known as the Archidamian War, Sparta launched repeated invasions of Attica while Athens took advantage of its naval supremacy to raid the Peloponnese coast. Sparta and its allies, with the exception of Corinth, were almost exclusively land-based powers, whereas the Athens empire, though based on a peninsula, had developed impressive naval power. As a result, the two powers were relatively unable to fight decisive battles.The Spartan strategy during the Archidamian War was to invade the land surrounding Athens, depriving Athenians of the productive land around their city. However, Athens maintained access to the sea and did not suffer much from this strategy, though many citizens of Attica abandoned their farms and moved inside the long walls connecting Athens to port Piraeus.

The Walls Protecting Athens. The walls protecting Athens during the Peloponnesian War. 

Initially Athens’ strategy, as guided by Pericles, was to avoid open battle with the more numerous, and better trained Spartan hoplites, and to instead rely on Athens’ superior fleet. As a result, Athens’ fleet went on the offensive, winning a victory at Naupactus. Their victory was short-lived, however, because in 430 BCE, an outbreak of plague hit Athens, ravaging the densely packed city and wiping out over 30,000 citizens, sailors, and soldiers, which amounted to roughly one-third to two-thirds of the Athenian population. As a result, Athenian manpower was drastically reduced, and due to widespread fears of plague, foreign mercenaries refused to hire themselves out to Athens. Sparta also abandoned its invasion of Attica during this time, unwilling to risk contact with their diseased enemy.

Pericles and his sons perished as a result of plague, and in the aftermath, Athenians turned against Pericles’s defensive strategy in favor of a more aggressive one that would bring war directly to Sparta and its allies. Initially this strategy met with some success as Athens pursued naval raids throughout the Peloponnese. Their successes allowed them to fortify posts throughout the Peloponnese. One such post was near Pylos, on a tiny island called Sphacteria. It began attracting helot runaways from Sparta, which in turn raised Spartan fears that Athenian activities throughout the Peloponnese would incite a mass helot revolt. As a result, the Spartans were driven into action. During the ensuing conflicts, 300 to 400 Spartans were taken hostage, providing Athens with a bargaining chip.

In return, the Spartans raised an army of allies and helots and marched the length of Greece to the Athenian colony of Amphipolis, which controlled several nearby silver mines. These mines were particularly important because they provided much of the money that financed the Athenian war effort. The capture of this colony provided Sparta a bargaining chip as well, and the two rival city-states agreed to sign a truce, exchanging the Spartan hostages for Amphipolis and its silver mines.

Peace of Nicias

The Peace of Nicias was signed in 421 BCE, concluding the first phase of the war. Due to the loss of war hawks in both city-states during the previous conflict, the peace endured for approximately six years. The treaty was undermined, however, by continued fighting and calls for revolt throughout the Peloponnese. Although the Spartans refrained from such actions themselves, their allies remained vocal, particularly Argos. The Athenians supported the Argives and encouraged them to form a coalition of democratic states within the Peloponnese and separate from Sparta. Early Spartan attempts to thwart such a coalition ultimately failed, and the Argives, their allies, and a small Athenian force moved to seize the city of Tegea, near Sparta.

The Battle of Mantinea was the largest land battle fought within Greece during the Peloponnesian War. The Argive allied coalition initially utilized the sheer strength of their combined forces to score early successes, but failed to capitalize on them, providing the elite Spartan forces opportunities to defeat the coalition and save their city from a strategic defeat. The Argive democratic alliance was broken up, and most members were reincorporated into Sparta’s Peloponnesian League, reestablishing Spartan hegemony throughout the region.

The Sicilian Expedition

During the 17^th year of war, Athens received news that one of their distant allies in Sicily was under attack from Syracuse. The people of Syracuse were ethnically Dorian like the Spartans, and Sicily and their allies, the Athenians, were ethnically Ionian. In 415 BCE, Athens dispatched a massive expeditionary force to attack Syracuse in Sicily. The Athenian force consisted of more than 100 ships, approximately 5,000 infantry, and lightly armored troops. However, their cavalry was limited to about 30 horses, which proved to be no match for the large and highly trained Syracusan cavalry.

Meanwhile, the Syracusans petitioned Sparta for assistance in the matter, and Sparta sent their general, Gylippus, to Sicily with reinforcements. Subsequent Athenian attacks failed and Athens’ entire force was destroyed by 413 BCE.

The Second War

This ushered in the final phase of the war, known as the Decelean War, or the Ionian War. By this time, Sparta was receiving support from Persia, and Sparta bolstered rebellions in Athens’ Aegean Sea and Ionian subject states, in order to undermine Athens empire. This eventually led to the erosion of Athens’ naval supremacy. The Lacedaemonians were no longer content with simply sending aid to Sicily as a means of supporting their ally. Instead, their focus shifted to an offensive strategy against Athens. As a result, Decelea, a town near Athens, was fortified in order to prevent the Athenians from making use of their land year-round, and to thwart overland shipments of supplies. Nearby silver mines were also disrupted, with Spartan hoplites freeing as many as 20,000 Athenian slaves in the vicinity. Due to this disruption in finance, Athens was forced to demand increased tribute from its subject allies, further increasing tension and the threat of rebellion throughout the Athenian empire.

Members of the Peloponnesian League continued to send reinforcements to Syracuse in hopes of driving off the Athenians, but instead, Athens sent another 100 ships and 5,000 troops to Sicily. Gylippus’s forces, combined with those of the Syracusans, defeated the Athenians on land. The destruction of Athens’ fleet at Aegospotami effectively ended the war, and Athens surrendered a year later in 404 BCE. Corinth and Thebes demanded that Athens be destroyed and all its citizens enslaved, but Sparta refused to destroy a city that had done good service at a time of great danger to Greece, and took Athens into their own alliance system.

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