The of the Watch was originally the commander of the ("guard watch") or ("number", meaning "regiment"), the third of the , professional cavalry regiments headquartered in and around
Constantinople, and distinct from the provincial or
thematic troops. The title of itself means "commander of a ", a term of
Gaulish origin which came to be used as a term for a kind of tactical cavalry formation in the
East Roman army of
Late Antiquity. The term (Greek: ) is not documented before the early 7th century but might have been used as an informal or unofficial designation before that date. The office and the corresponding unit appear to have initially referred to
ad hoc arrangements, but during the early 7th century these were formalized, like much of the East Roman army's rank structure. Judging from the unit's name and the peculiar titles of its officers, it also had a considerable ancestry, dating back to the East Roman army, but it is unknown exactly when it was constituted as a . The office of the of the Watch at any rate is first attested , when
Alexios Mosele is recorded as " and of the Watch". In contrast to the other , the Watch and its commanders had special duties related to the safety of the Emperor and the imperial palace. Within Constantinople, the Watch provided guards for the
palace precinct, and kept a permanent garrison at the
Covered Hippodrome (which was also the 's seat). As detailed in the
De Ceremoniis, the of the Watch always accompanied the Emperor and was a frequent participant in various imperial ceremonies, often accompanied by his principal aide, the . His ceremonial dress is indicated as the tunic and a red cloak, while on some occasions he bore a sword, a
mace and an axe. The latter weapon was highly unusual for a Byzantine officer, and the French scholar
Rodolphe Guilland suggests that this was connected to his command of foreign troops via the (who later notably became the commander of the axe-bearing
Varangian Guard). In the 10th century, when several holders of the post were scions of the most prominent families of the military aristocracy, including
Eustathios Argyros,
John Kourkouas and
Manuel Kourtikes, the occupied the 36th place in the imperial hierarchy and usually held the senior court dignities of , or .
List of known holders :
Note: the list does not include holders known only through their seals but otherwise unidentified, or anonymous holders. == Judicial office ==