At the beginning of 522 BCE, Darius (ruled 521—486 BCE) was 28 years of age and, according to the Greek historian Herodotus, one of the king’s spear-bearers in Egypt. It seems likely that as soon as Cambyses died, Darius left the army and hastened back to Media to join with a party of nobles to usurp the usurper.
After almost two years of civil strife all over the empire, Darius finally succeeded in quelling all opposition and took the Persian throne as Darius I. On the Behistun Inscription (see box, page 137) Darius claimed his right to rule through his descent from princes of the royal blood. Darius also claimed that Cambyses had slain Bardiya before going to Egypt and that it was an imposter, Gaumatan, who had rebelled in Bardiya’s name.
The first imperative for Darius on ascending the throne was to restore order in a war-torn empire. Darius was an able administrator, and he set about restoring and strengthening the system of satrapies (provinces) that had been instituted by Cyrus II. The empire was divided into 20 satrapies, each a vast territory ruled over by a satrap (governor) who was directly responsible to the king. Each province also had a military commander who took instructions directly from the king, thereby ensuring military supervision of the whole empire. In addition,
This frieze shows how soldiers would have dressed during the reign of Darius I. The frieze originally adorned the walls of the king's palace.