The Peloponnesian War pitted Athens against Sparta in a 27-year struggle that reshaped ancient Greece. Growing tensions between the two powerful city-states, fueled by Athens' rising influence and ideological differences, eventually erupted into all-out conflict.

The war unfolded in two main phases: the Archidamian War and the Decelean War. Key events like the Sicilian Expedition and the plague in Athens had major impacts. The conflict ended with Sparta's victory, dramatically altering the balance of power in the Greek world.

Causes of the Peloponnesian War

Growing Tensions between Athens and Sparta

• The Peloponnesian War was a protracted conflict between the city-states of Athens and Sparta that lasted from 431 to 404 BCE
• The war was primarily caused by the growing power and influence of Athens, which threatened Sparta's traditional hegemony in the Greek world
  • Athens had become the dominant naval power in the Aegean Sea, while Sparta maintained its supremacy on land
  • The Delian League, led by Athens, had evolved into an Athenian empire, with Athens exerting control over its allies and extracting tributes from them
• The ideological differences between Athens, a democratic city-state, and Sparta, an oligarchic society, also contributed to the growing hostility between the two powers

Immediate Triggers for the War

• The immediate trigger for the war was a series of disputes between Athens and Sparta's allies, particularly Corinth and Megara
  • In 433 BCE, Athens imposed economic sanctions on Megara, a Spartan ally, which was seen as an act of aggression by Sparta
  • Corinth, another Spartan ally, was involved in conflicts with its colony Corcyra, which sought help from Athens, further escalating tensions
• These disputes, combined with the underlying tensions between Athens and Sparta, ultimately led to the outbreak of the Peloponnesian War in 431 BCE

Peloponnesian War: Major Events

The Archidamian War (431-421 BCE)

• The Archidamian War began with Sparta invading Attica, the region around Athens, while Athens relied on its naval supremacy to attack Sparta's coastal allies
  • The Athenian statesman Pericles adopted a defensive strategy, bringing the population within the city walls and avoiding direct confrontation with the Spartan army
  • The crowded conditions in Athens led to a devastating plague that killed a significant portion of the population, including Pericles himself
• The Peace of Nicias was a truce that lasted for six years, but it was ultimately unsuccessful in resolving the underlying conflicts between Athens and Sparta

The Sicilian Expedition and the Decelean War (415-404 BCE)

• The Sicilian Expedition (415-413 BCE) was a turning point in the war, as Athens launched a massive campaign to conquer the island of Sicily, which ended in a disastrous defeat for the Athenians
  • The Athenian fleet was destroyed, and the expeditionary force was either killed or captured, significantly weakening Athens' military and financial resources
• In the Decelean War, Sparta, with the support of the Persian Empire, adopted a more aggressive strategy, establishing a permanent base in Attica and supporting rebellions among Athens' allies
• The final blow to Athens came in 405 BCE when the Spartan general Lysander decisively defeated the Athenian fleet at the Battle of Aegospotami, leading to Athens' surrender in 404 BCE

Athenian vs Spartan Strategies

Athens' Defensive Strategy

• Athens, with its powerful navy and fortified city walls, adopted a largely defensive strategy on land while using its fleet to attack Sparta's allies and maintain control over its empire
  • The Periclean strategy involved avoiding direct confrontation with the Spartan army, relying on Athens' naval supremacy and the city's strong walls for protection
  • Athens also used its financial resources to maintain its fleet and fund military campaigns, such as the Sicilian Expedition
• The Sicilian Expedition demonstrated the risks of Athens' aggressive imperial strategy, as the devastating defeat significantly weakened the city's military and financial capabilities

Sparta's Land-based Offensive

• Sparta, on the other hand, relied on its superior land forces and the support of its allies to pressure Athens and undermine its power
  • Sparta repeatedly invaded Attica, burning crops and devastating the countryside, in an attempt to force Athens into a decisive battle
  • Sparta also sought to foment rebellions among Athens' allies, particularly during the Decelean War, to weaken Athens' control over its empire
• Both sides also engaged in diplomacy and propaganda to win support from other Greek city-states and even foreign powers like the Persian Empire
  • Sparta ultimately secured financial and naval support from Persia, which proved crucial in the later stages of the war

Key Figures in the Peloponnesian War

Athenian Leaders

• Pericles, the influential Athenian statesman, was instrumental in formulating Athens' defensive strategy during the early stages of the war
  • Pericles advocated for a policy of avoiding direct confrontation with the Spartan army, instead relying on Athens' strong walls and naval supremacy to wear down the enemy
  • His death during the plague in 429 BCE was a significant blow to Athens, as subsequent leaders proved less effective in managing the war effort
• Alcibiades, a controversial Athenian politician and general, played a complex role in the war, switching allegiances between Athens and Sparta
  • Alcibiades was a key proponent of the Sicilian Expedition, which he saw as an opportunity to expand Athens' power and his own prestige
  • However, he was accused of sacrilege on the eve of the expedition and fled to Sparta, where he advised the Spartans on how to defeat Athens
  • Later, Alcibiades returned to Athens and led successful campaigns against Sparta, but his political enemies ultimately forced him into exile once again
• Nicias, an Athenian general and politician, was a leading advocate for peace with Sparta and opposed the Sicilian Expedition
  • Despite his reservations, Nicias was appointed as one of the commanders of the expedition, along with Alcibiades and Lamachus
  • After Alcibiades' defection and Lamachus' death, Nicias was left in sole command of the ill-fated expedition, which ended in a disastrous defeat for Athens

Spartan Leaders

• Lysander, a Spartan general, played a crucial role in the final years of the war, securing Persian support and reforming Sparta's navy
  • Lysander's decisive victory over the Athenian fleet at Aegospotami in 405 BCE effectively ended the war, leading to Athens' surrender and the end of its empire
• Lysander's military successes and political influence helped shape the post-war Greek world, with Sparta emerging as the dominant power in the region