1) Cyrus the Great ruled the Persian Empire from 559 to 530 BCE and was known for treating his subjects well. Darius later reorganized the empire into 20 provinces to make it more efficient to govern.
2) Xerxes, son of Darius, vowed revenge on Athens for helping a rebellion and led a second Persian invasion of Greece in 480 BCE. Themistocles devised a strategy to defeat the Persians by cutting off their food supply.
3) Herodotus documented the Persian Wars in his work "The Histories", describing the conflict as between freedom and dictatorship. This work is considered one of the first real histories in Western civilization.