Under the emperor Cyrus (r. 559-529 B. C.), the Persians built a 1,500-mile road from Sardis in Asia Minor to the Persian capital at Susa. At the time of its building, the "Royal Road" was the longest in the world. Even compared with the interstate highways of the United States today, it is impressive. Interstate 75, which runs from the Canadian border in Michigan all the way to the southern end of Florida, is barely as long. One of the few U. S. interstates longer than the Royal Road is I-80, which runs for nearly 2,500 miles from New York City to San Francisco, California.
The Royal Road made possible one of the world's first postal systems. Along it lay some 80 stations, where one horsebound mail carrier could pass the mail on to another, a system not unlike the
Pony Express used in the American West during the 1860s.
Mail in the Persian Empire, however, was not just for anyone: only the king and important leaders such as the satraps could use the postal system. The idea of ordinary people being able to mail letters did not take hold until the 1600s in England.
Nonetheless, the Persian messenger system was so efficient—the mail carriers did their job so well—that the Greek historian Herodotus wrote of them, "Neither snow, nor rain, nor heat, nor gloom of night stays [prevents] these couriers from the swift completion of their appointed rounds." These lines are inscribed on the front of the central post office building in New York City.
More, the official view of taxes was that everything belonged to the king and that the people who owned houses or lands were simply "renting" them from him. Later, as taxes rose, this had a crippling effect on the Persian economy and helped to bring about the empire's downfall.