Ruler of the Achaemenid Persian empire 486–465 bc. He personally led the great expedition against Greece, but after watching his fleet being defeated at Salamis in 480 bc, he withdrew, leaving behind Mardonius under whose command the army was defeated at Plataea in 479. The subsequent activities of the Delian League deprived him of many Greek cities in Asia Minor. The latter part of his reign was marked by intrigues, one of which led to his murder.