He had such a huge empire that he divided it into smaller provinces, so it could be ruled efficiently by local officials. He had the government build good roads to tie the empire together. This made it possible for the armies to move around more easily and improved trade. Darius also built a canal connecting the Red Sea to the Nile River. A common coin was adopted for the empire, and the same system of weights and measures was used by everyone, so people from one area could trade more easily with people from another area. Aramaic was the spoken language. Even with such a vast empire, people from one area could connect with people from far away corners of Persia because of good roads, the similarity of language, and uniform standards for money, weights and measures.

The Persians sent letters on horseback to all parts of the empire. This was one of the most organized early postal systems. In fact, it was so well-managed that Herodotus, a Greek historian who lived around 450 B.C., said of it, “Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds.” This has become a famous statement, and it can be found carved over the main post office of the United States in New York City.

King Darius I was known for his belief in the importance of good laws, and he borrowed heavily from the laws of Hammurabi. He left many written messages on the walls of Persepolis, and the following statement, which accurately sums up the Persians’ passion for truth, was among them:

I am of such a character: what is right I love and what is not right I hate... The man who decides for the Lie I hate... And whoever injures, according to what he has injured I punish... Of the man who speaks against the Truth, never do I trust a word.