ANGARIA

Roman imperial postal system modeled on that of Achaemenidian Persia, probably originally established in the 6th century BC by Cyrus the Great. The name was derived from the Greek form of a Babylonian word meaning a mounted courier, the means used to carry royal dispatches by night and day in all weather. The angaria presumably survived in Hellenistic times and passed down to the Romans. In the Roman system, the supply and maintenance of post horses was a compulsory duty from which the emperor alone could grant exemption; thus, the word came to mean compulsory service.