The Angarium (Latin; from Greek Greek, Ancient (to 1453);: Ἀγγαρήιον) was the institution of the royal mounted couriers in ancient Persia. The messengers, called (Greek, Ancient (to 1453);: ἄγγαρος), alternated in stations a day's ride apart along the Royal Road. The riders were exclusively in the service of the Great King and the network allowed for messages to be transported from Susa to Sardis (2699 km) in nine days; the journey took ninety days on foot.[1]
Herodotus, in about 440 BC, describes the Persian messenger system which had been perfected by Darius I about half a century earlier:
A sentence of this description of the, translated as "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds," is famously inscribed on the James A. Farley Building in New York City.