Athens and Sparta destroy each other, slowly
What happened
Long-simmering rivalry between Athens, the dominant naval power, and Sparta, the dominant land power, broke into open war in 431 BCE, dragging in allied city-states across the Greek world for 27 years. Spartan armies invaded Athenian territory nearly every year, burning farms and olive groves the Athenians could not easily replant, while Athens retreated behind its fortified Long Walls and resupplied itself by sea, absorbing a devastating plague in 430 BCE that killed a large share of its population, Pericles included. Athens gambled its fleet and army on a massive, ultimately disastrous invasion of Sicily in 415 to 413 BCE, and the war's outcome was finally settled not on land but at sea: in 405 BCE, the Spartan admiral Lysander destroyed the Athenian fleet at Aegospotami using ships built with Persian money, and Athens, unable to build another navy or feed itself, surrendered in 404 BCE.
Why it matters
The surrender terms, tearing down Athens's Long Walls and capping its navy at 12 ships, ended Athens's empire outright, but Sparta's own victory proved just as fragile: within a decade Sparta was fighting most of its former allies, and within a generation Thebes had broken Spartan military dominance for good. The real long-term winners were Persia, which had funded Sparta's fleet, and eventually Macedon, which inherited a Greek world too exhausted and divided to resist Philip II.
How we know
The historian Thucydides began recording the war as it happened, a contemporary participant rather than a later chronicler, and though his account breaks off before the war's end, it remains one of the most detailed firsthand records of any conflict from antiquity.
Sources
- World History Encyclopedia. Peloponnesian War · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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