Hemerodromoi

Hemerodromoi (Ancient Greek: ἡμεροδρόμοι, lit.'day-runners') or hemeroskopoi (Ancient Greek: ἡμεροσκόποι, lit.'day-watchers') or dromokerykes (Ancient Greek: δρομοκήρυκες, lit.'runner heralds') were specialized couriers in ancient Greece renowned for their exceptional endurance.