The Battle of Thermopylae was part of which larger conflict?

The Battle of Thermopylae was part of the Greco-Persian Wars. It was fought in 480 BC during Xerxes I's second major invasion of Greece, when the Achaemenid Persian Empire sought to defeat the independent Greek city-states.

The conflict began with tensions surrounding the Ionian Revolt and the Greek support given to cities rebelling against Persian rule. Persia's first invasion ended with its defeat at Marathon in 490 BC. A decade later, Xerxes launched a much larger invasion by land and sea.

Thermopylae formed part of a coordinated Greek defensive strategy. While Leonidas and the army blocked the Persian advance at the pass, the Greek fleet confronted the Persian navy at Artemisium. After Thermopylae fell, Persia captured Athens, but the Greeks later won crucial victories at Salamis and Plataea.

The battle is sometimes described as a Greek victory because of its heroic resistance, but militarily it was a Persian victory: the pass was taken and the Greek defenders were destroyed. Its lasting importance lies in its place within the wider wars and the example of resistance it created.