Darius I was the third king of the Persian Achaemenid Empire. Also called Darius the Great, he ruled the empire at its peak, when it included much of West Asia, the Caucasus, parts of the Balkans (Thrace-Macedonia and Paeonia), most of the Black Sea coastal regions, parts of the North Caucasus, Central Asia, as far as the Indus Valley in the far east, and portions of north and northeast Africa including Egypt (Mudraya), eastern Libya and coastal Sudan.