1 · POSITION
The Royal Road ran about 2,700 kilometres from Susa to Sardis, reorganised and rebuilt by the Achaemenid kings in the fifth century BC. Along it stood 111 posting stations with fresh horses. It is entered here as the first road in the register built round a chain of stations — a bed and a horse a day’s ride apart — kept by an empire for its own messengers. [1, 2]
2 · THE RELAY
Cyrus the Great established the post and Darius developed it. Couriers changed horses at stations about a day’s ride apart and received fresh mounts and supplies at each, so they never waited to find either. A message could cross the empire in about nine days; on foot the same road took ninety. The Persians called the relay the angarium, and the riders served only the king. [1, 2]
3 · HERODOTUS COUNTS THE STATIONS
Herodotus described the road and counted its stations — one hundred and eleven between Sardis and Susa — and wrote that nothing in the world travels faster than these Persian couriers. His description of riders stopped by neither snow nor rain nor heat nor gloom of night is inscribed on the James Farley post office in New York and is taken as the unofficial creed of the American postal service. [1, 2]
4 · WHAT CAME AFTER
The Romans adopted the system as the cursus publicus, and the Ottomans kept stations of the same name, the çaparhane, for official messages and the lodging of troops. [2]
5 · ⚑ CANDOUR
⚑ Checked on 22 October 2026. Herodotus counts 111 stations and about four parasangs between them; the register’s fifteen to twenty miles was a conversion the sources read do not make, and the note now gives Herodotus’ own count. The western sections may be older than the Achaemenids. The American postal service has no official motto. [1–3]
Sources & Further Reading
Sources checked 22 October 2026.