Darius I was the third king of the Achaemenid Empire. He extended the empires borders into India and Europe. He also fought two wars with the Greeks which were disastrous. Darius established a government which became a model for many future governments:

Established a tax-collection system;

Allowed locals to keep customs and religions;

Divided his empire into districts known as Satrapies;

Built a system of roads still used today;

Established a complex postal system;

Built two new capital cities, one at Susa and one at Persepolis.