Cyrus the Great’s Conquests
The estimated expanse of the Achaemenid Empire at its height c. 500 BCE was two million square miles. Most of this territory was conquered by Cyrus the Great, the founder of the Empire, who reigned from 559 to 530 BCE, the fourth king in his dynastic line as relayed in the opening quote from the Cyrus Cylinder, a foundational text for the study of Cyrus.