The tzaousios (Greek: τζαούσιος) was a late Byzantine military office, whose exact functions and role are somewhat unclear.
[1] The term is derived from the Turkish çavuş, meaning "courier" or "messenger",[1] and was in use by the Byzantines perhaps as early as the late 11th century.
[1][2] Most of the tzaousioi mentioned in the sources came from the Byzantine Morea,[3] where they played an important role in provincial administration.
[4] The French Byzantinist Rodolphe Guilland suggested that he was in command of subordinated tzaousioi, who acted as the successors of the earlier imperial courier corps, the mandatores.
[3] Certainly, the first megas tzaousios, Constantine Margarites, was the commander of Vatazes's personal retinue,[6] but in later times, the title does not appear to have corresponded to a specific function.