The Royal Road was an ancient highway reorganized and rebuilt by the Persian king Darius the Great (Darius I) of the first (Achaemenid) Persian Empire in the 5th century BC. Darius built the road to facilitate rapid communication throughout his very large empire from Susa to Sardis ("centralized rule is the victim of time and distance," Robin Lane Fox has observed in this context). Mounted couriers could travel 1677 miles (2699 km) in seven days; the journey from Susa to Sardis took ninety days on foot. The Greek historian Herodotus wrote, "There is nothing in the world that travels faster than these Persian couriers." Herodotus's praise for these messengers—"Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds"— was inscribed on the James Farley Post Office in New York and is sometimes thought of as the United States Postal Service creed.