Michael Nicholson, Corbis

The flooding dark about their knees / The mountains over Persia change. Founded in the mid-sixth-century B.C. by the Achaemenid king Cyrus, the Persian Empire (in modern Iran) once controlled all of western Asia and the Near East. It reached its zenith under the leadership of Darius I (521–486 B.C.), a brilliant general and dynamic administrator who annexed the Levant and Egypt, invaded Greece, quelled rebellions in Babylonia and launched a widesread program of public improvements throughout the realm. Darius’s terraced palace at Persepolis was one of the great architectural achievements of the ancient world. (The stone staircase shown above is from the palace’s famous apadana, or audience hall.) Most of Persepolis was burned to the ground, along with the Achaemenid kings’ summer residence at Ecbatan (modern Hamadan), when Alexander the Great invaded Persia in 331 B.C.