The Sicilian Expedition, the role of Persia and Lysander, and the final defeat and surrender of Athens in 404 BC

What this dot point is asking

SCSA wants you to understand the decisive later phases of the Peloponnesian War: the catastrophic Sicilian Expedition, the entry of Persian money on the Spartan side, and the naval defeats that finally broke Athens. You need to explain why the Sicilian venture failed, how Persia and the Spartan commander Lysander turned the war, and how Athens came to surrender in 404 BC. The Greece option is examined through source analysis and essays, so you must name and evaluate evidence such as Thucydides, whose narrative breaks off, and its continuation by Xenophon, alongside Plutarch.

The Sicilian Expedition of 415 to 413 BC was the great gamble that broke Athenian power. After the inconclusive first phase of the war and the fragile Peace of Nicias, the ambitious Alcibiades persuaded the assembly to send a vast fleet and army to conquer Syracuse, the most powerful city in Sicily, promising wealth and strategic advantage. The cautious general Nicias opposed the scheme but was appointed to lead it alongside Alcibiades, an unstable command from the start. Thucydides presents the decision as a fateful example of Athenian overreach and the recklessness of the democracy after Pericles.

The expedition was undermined before it could succeed. On the eve of departure Athens was convulsed by the religious scandal of the Mutilation of the Herms, sacred statues defaced overnight, and Alcibiades was implicated in related impieties. Recalled to stand trial, he instead defected to Sparta, where he advised the enemy on how to defeat Athens, including the recommendation to send a Spartan commander to Syracuse and to fortify Decelea. Deprived of its most dynamic leader and left under the hesitant Nicias, the siege of Syracuse stalled and then collapsed. In 413 BC the entire expedition was annihilated, the fleet destroyed and the survivors killed or worked to death in the quarries.

The disaster transformed the war. On Alcibiades' advice Sparta permanently fortified Decelea in Attica from 413 BC, occupying Athenian territory year-round, disrupting agriculture and the silver mines and encouraging slaves to desert. More decisively, Sparta now sought the one resource it lacked, money to build and maintain a fleet capable of challenging Athens at sea, and found it in Persia. The Persian satraps, eager to recover the Greek cities of Asia Minor, agreed to fund a Spartan navy in exchange for Spartan concessions over those cities. Persian gold thus tipped the naval balance that had always favoured Athens.

The final phase, the Ionian or Decelean War, was fought largely at sea around the Aegean and was marked by Athenian resilience and recurring crisis. Athens suffered the oligarchic coup of the Four Hundred in 411 BC before democracy was restored, and won naval victories, notably at Cyzicus, partly under the recalled Alcibiades. But after the costly victory at Arginusae in 406 BC the Athenians executed their own victorious generals for failing to rescue survivors, a self-destructive act that deprived them of leadership. Thucydides' narrative breaks off in 411 BC, so for these events the chief source becomes Xenophon's Hellenica, which continues the story but with a more pro-Spartan and less analytical character.

The end came swiftly through the Spartan admiral Lysander. Backed by Persian money, especially through his relationship with the prince Cyrus the Younger, Lysander built and maintained a strong fleet and outmanoeuvred the Athenians. In 405 BC he caught the Athenian navy beached and unprepared at Aegospotami in the Hellespont and destroyed it almost completely, severing Athens' vital grain route from the Black Sea. Blockaded and starving, Athens surrendered in 404 BC. The terms stripped it of its empire and fleet and required the demolition of the Long Walls, and Lysander installed a narrow pro-Spartan oligarchy, the Thirty Tyrants, whose brief and brutal rule Xenophon records.

This dot point matters because it explains the war's outcome and consequences. The Sicilian disaster, Persian intervention and Lysander's naval victory together brought down the Athenian empire and ended the war, reshaping the balance of power in Greece and leaving Sparta temporarily dominant. Understanding why the expedition failed, how external money and sea power proved decisive, and how the sources shift from Thucydides to Xenophon allows you to analyse both the events and the changing quality of the evidence.