550-486 B.C.

King of Persia who reorganized the empire into provinces called satrapies, which were ruled by governors. Under his regime an efficient postal system was devised and royal roads were constructed. Darius is also credited with initiating the development of a cuneiform script to represent the Persian language. The Persian army, sent by Darius to punish a Greek revolt, was defeated by the Greek states at Marathon in 490 B.C., one of the most famous ancient battles.