(compounded of ἡμέρα, "day," and δρόμος, "course," &c.) among the ancients, were sentinels or guards, appointed for the security and preservation of cities and other places. They went out of the city every morning, as soon as the gates were opened, and kept all day patrolling round the place; sometimes also making excursions farther into the country, to see that there were no enemies lying in wait to surprise them.

HEMERODROMI were also a fort of couriers among the ancients, who only travelled one day, and then delivered their packets or dispatches to a fresh man, who run his day, and so on to the end of the journey. The Greeks had coursers of this kind, which they derived from the Persians, who were the inventors thereof, as appears from Herodotus. Augustus had the fame; at least he established coursers, who, if they did not relieve each other from day to day, yet did it from space to space, and that space was not very great.