The Achaemenid Empire, or Achaemenid Persian Empire, (550–330 BC) was the first of the Persian Empires to rule over significant portions of Greater Persia (or Iran). It followed the Median Empire as the second great empire of the Iranian peoples.At the height of its power, the Achaemenid Empire had about 7.5 million square kilometers and was territorially the largest empire of classical antiquity.
The empire was forged by Cyrus the Great. It spanned three continents, including parts of Afghanistan and Pakistan; parts of Central Asia, Asia Minor, Thrace; much of the Black Sea coastal regions; Iraq, northern Saudi Arabia, Jordan, Israel, Lebanon, Syria; and all significant population centers of ancient Egypt as far west as Libya. The empire was the foe of the Greek city-states in the Greco-Persian Wars. It freed the Israelites from their Babylonian captivity, and instituted Aramaic as the empire's official language. Because of the Empire's vast extent and long endurance, Persian influence upon the language, religion, architecture, philosophy, law and government of nations around the world lasts to this day.