Darius was a prominent king of the ancient Persian Empire, ruling from 522 to 486 BCE. He is best known for his administrative reforms, which helped to unify and expand the empire. Darius introduced a system of provinces, known as satrapies, each governed by a satrap to maintain order and collect taxes. Under Darius's leadership, the Persian Empire reached its greatest territorial extent, stretching from Egypt to parts of India. He also initiated the construction of the famous Royal Road, which facilitated trade and communication across the vast empire. Darius is often remembered for his contributions to infrastructure and governance.