The Achaemenid Persian empire was the largest that the ancient world had seen, extending from Anatolia and Egypt across western Asia to northern India and Central Asia. Its formation began in 550 B.C., when King Astyages of Media, who dominated much of Iran and eastern Anatolia (Turkey), was defeated by his southern neighbor Cyrus II (“the Great”), king of Persia (r. 559–530 B.C.).Much of our evidence for Persian history is dependent on contemporary Greek sources and later classical writers, whose main focus is the relations between Persia and the Greek states, as well as tales of Persian court intrigues, moral decadence, and unrestrained luxury.