What Was the Biggest War in Ancient Greece?

Ancient Greece was a time of great conflict and war. With many city-states vying for power, it was only a matter of time before tensions boiled over into full-scale warfare. While there were many wars fought in ancient Greece, one stands out as the biggest and most significant of them all – the Peloponnesian War.

The Peloponnesian War

The Peloponnesian War was fought between Athens and Sparta from 431-404 BCE. It was named after the Peloponnesian Peninsula, which is where Sparta was located. The war began when Athens formed an alliance with the city-state of Corcyra, which Sparta saw as a threat to its power.

The Outbreak of War

The first phase of the war lasted from 431-421 BCE. During this time, both sides suffered heavy losses, but neither was able to gain a decisive advantage over the other. In 421 BCE, a peace treaty known as the Peace of Nicias was signed between Athens and Sparta.

The Sicilian Expedition

However, the peace was short-lived. In 415 BCE, Athens launched an ambitious invasion of Sicily in an attempt to expand its empire. The expedition ended in disaster when most of the Athenian fleet was destroyed and thousands of soldiers were killed or captured.

The Final Phase

The final phase of the war began in 413 BCE when Sparta gained control of Athens’ port city at Pylos. This allowed them to cut off Athens’ supply lines and starve the city into submission. In 404 BCE, Athens finally surrendered, bringing an end to one of the longest and most devastating wars in ancient history.


The Peloponnesian War was undoubtedly the biggest war in ancient Greece. It lasted for over 25 years and involved most of the major city-states of the time.

The war had a profound impact on Greek society, leading to the decline of Athens and the rise of Sparta as the dominant power in Greece. Today, it serves as a cautionary tale about the dangers of unchecked ambition and the high cost of war.