Answer: Greeks had helped cities that were rebelling against the Persians.
Explanation:
Persia's attack on Greece was revenge for the Athenian incitement of the Ionian uprising in Asia Minor. From 499 to 493 BC, a series of uprisings against the Persian government in Asia Minor took place. The cause of these uprisings was Greek discontent against the Persian administration in that part of the world. Because of that act, Parzia attacked Greece.
