A bas-relief from Persepolis showing Darius fighting a monster.
Darius I was king of ancient Persia who succeeded Cambyses, son of Cyrus (founder of the Persian Empire). Darius enlarged the Persian Empire so that its frontiers reached to India. With peace established, he devoted himself to organizing his vast territory, which he divided into provinces called satrapies, after the name of their governors who were called satraps. In order to foster trade and the welfare of his people, Darius made gold and silver coins, built great roads, the most famous of which was 1,500 miles long and linked Susa (today's Shushtar) with Sardes, which is near Smyrna.
Darius is famous in history for his military expedition against Greece. He wanted to punish the city of Athens because it had supported the revolt of the Greek towns of Asia Minor, which were part of his empire. He prepared a large army which he landed on the shores of the bay of Marathon, 26 miles from Athens. But his army was defeated by Miltiades in the year 490 BC.