Darius I improved the Persian government by dividing the Persian Empire into provinces and implementing numerous construction projects. Theses projects included the construction of a new capital at Persepolis and roads throughout the empire.
Known as Darius the Great, Darius I was born in 550 B.C. and ruled from 522 B.C. until his death in 486 B.C. Before Darius, the Persian Empire was loosely organized. He established 20 provinces, or satrapies, each ruled by a satrap. He imposed security measures that reduced the likelihood of revolt by the satraps.
Construction of Persepolis, which replaced the previous capital at Pasargadae, began around 515 B.C. The new buildings in Persepolis included palaces, audience and debating halls, and the main imperial treasury. The roads built by Darius included the Royal Road, which ran from the Aegean Sea to Persia, a distance of 1500 miles. This road allowed Persian officials to reach conquered cities throughout the empire, and messenger stations along the road facilitated the post and other communications.
Under Darius, the network of irrigation projects in the empire expanded. He also introduced a universal currency, the daric. In Egypt, which Persia ruled, Darius built a canal from the Nile to the Red Sea. The codification of Egyptian law was completed during his reign.