Battle of Marathon

After gaining control of the rebellious Ionian Greeks in 495 BC, Darius I of Persia realized that they would be a perpetual bother as long as they could gain help and encouragement from the Greek mainland so he determined to conquer Greece proper, secure his western frontier and lay the groundwork for Persia's expansion into Europe. He was also outraged that during the Ionian rebellion an obscure city-state (Athens) from mainland Greece had assisted in the expulsion of the Persians from Sardes, the capitol of the Ionian Greek city-states. His anger was such that he vowed to punish them and every night at dinner he had a servan repeat to him "Lord, don't forget the Athenians" [Ancient Greece]

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