In 491 BC the 'Great King', Darius, who ruled the vast Persian Empire, sent envoys to the Greek city-states seeking 'earth and water' - tokens of submission to Persian authority. Darius had been provoked by the assistance the city-states, particularly Athens, had given to an unsuccessful revolt by the Ionian Greeks - the colonies of Greeks living on the western coast of Turkey. In retaliation he now sought to establish his authority over all Greece.

In Athens, Darius' envoys were thrown into a pit reserved for those condemned to death and Themistocles lobbied unsuccessfully to have them executed on a charge of defiling the Greek language with their 'barbarian demands'.

Elsewhere in Greece, many city-states simply submitted. Only Sparta dared to treat the envoys with the same disregard as Athens. They threw the envoys down a well and told them to find their water there.

A furious King Darius readied his forces...