The causes, key phases and consequences of the Peloponnesian War and the role of leaders such as Pericles, Alcibiades and Lysander

What this dot point is asking

SCSA wants you to study the Greek world across the period of the Peloponnesian War, from its outbreak in 431 BC to the surrender of Athens in 404 BC, as a defined historical period. You need to explain why Athens and Sparta fought, the main phases of the war, and its consequences for Greek power, with attention to the exercise of power and authority and the role of key individuals. The Greece option is examined through source analysis and essays, so you must name and evaluate evidence above all Thucydides, alongside Plutarch, Xenophon and the Old Oligarch.

The war's causes are debated because our chief source frames them. Thucydides, an Athenian general exiled during the war, wrote a history that aimed at lasting analytical value, and he distinguishes the immediate grievances from the underlying cause. The immediate triggers included Athenian intervention at Corcyra and Potidaea and the Megarian Decree, an economic blockade of Megara, a Spartan ally. But Thucydides famously argues that the truest cause, least openly stated, was that the growth of Athenian power frightened Sparta and made war inevitable. Modern historians such as Donald Kagan have challenged this sense of inevitability, stressing avoidable miscalculations, which makes the causes a rich essay topic.

The Archidamian War (431 to 421 BC) takes its name from the Spartan king Archidamus. Pericles' strategy was to abandon the Attic countryside, bring the population inside the Long Walls connecting Athens to its port at Piraeus, and rely on naval supremacy and imperial revenue. The strategy was sound but the crowded city suffered a devastating plague from 430 BC, which killed perhaps a quarter to a third of the population, including Pericles himself in 429 BC. Thucydides' eyewitness account of the plague is a famous and reliable source. The war then continued under more aggressive leaders such as the demagogue Cleon, with Athenian success at Pylos in 425 BC, until the deaths of Cleon and the Spartan Brasidas at Amphipolis in 422 BC opened the way to the Peace of Nicias in 421 BC.

The fragile peace collapsed through renewed ambition. The brilliant but unreliable Alcibiades pushed Athens toward an anti-Spartan coalition that was crushed at Mantinea in 418 BC, and in 416 BC Athens infamously besieged the neutral island of Melos, executing the men and enslaving the women and children. Thucydides dramatises this in the Melian Dialogue, a chilling debate on the nature of imperial power in which the Athenians argue that the strong do what they can and the weak suffer what they must. The episode is essential evidence for the exercise of power and a favourite source-analysis text.

The turning point was the Sicilian Expedition of 415 to 413 BC. Persuaded by Alcibiades, Athens sent a vast fleet to conquer Syracuse. The venture was crippled from the start: the religious scandal of the Mutilation of the Herms led to Alcibiades being recalled for trial, whereupon he defected to Sparta and advised the enemy. The cautious general Nicias mismanaged the siege, and in 413 BC the entire expedition was destroyed, its survivors killed or worked to death in the quarries. Thucydides presents this as the great catastrophe that broke Athenian power.

The final phase, the Decelean or Ionian War, sealed Athens' fate. On Alcibiades' advice Sparta fortified Decelea in Attica permanently and, decisively, accepted Persian money to build a fleet that could challenge Athens at sea. Internal crisis followed with the oligarchic coup of the Four Hundred in 411 BC. Despite an Athenian recovery under the recalled Alcibiades, the Spartan admiral Lysander, backed by Persian gold, destroyed the Athenian fleet at Aegospotami in 405 BC. Besieged and starving, Athens surrendered in 404 BC, lost its empire and Long Walls, and briefly suffered the rule of the pro-Spartan Thirty Tyrants, an episode recorded by Xenophon, whose Hellenica continues the narrative after Thucydides breaks off.

Historiographically, the period is dominated by Thucydides, which is both a strength and a danger. His analytical rigour and eyewitness access make him invaluable, yet the speeches he composes are his own reconstructions, he writes from an Athenian and exiled perspective, and his narrative is incomplete. Plutarch's later Lives of Pericles, Nicias and Alcibiades add detail but draw on lost sources and a moralising agenda, while the Old Oligarch offers a hostile contemporary view of Athenian democracy. Strong answers weigh these sources against each other rather than treating Thucydides as the unquestioned truth.