Darius I (c. 550-486 BCE), also known as Darius the Great, was the third Persian King of the Achaemenid Empire. His reign lasted thirty-six years, from c. 522 to 486 BCE; during this time the Persian Empire reached its peak. Darius led military campaigns in Europe, Greece, and even in the Indus Valley, conquering lands and expanding his empire. Not only resuming to military prowess, Darius also improved the legal and economic system and conducted impressive construction projects across the Persian Empire.
- Darius at the Ancient History Encyclopedia (Retrieved on October 18, 2017)