The Persian Wars began when the helped the Ionian people revolt against the Persians. From that time, the Greeks and Persians became enemies. They fought a series of wars over 50 years. started the first war to punish the Greeks for their support of the Ionian revolt. The Greeks defeated his forces at the . But after his death, his son Xerxes I sent the Persian military to invade Greece again. In 479 BC, the fighting ended with .