The adjective Comitatensis, plural Comitatenses is derived from the Latin comitatus, meaning "retinue". In the first and second centuries AD, the comitatus was understood as a retinue of Roman emperors, consisting of his friends and associates.
At the end of the third century AD, the term comitatus still refers to the emperor's personal guard.
For the first time, comitatenses as a special class of soldiers are legally attested in the decree of Constantine of 325 and implies the most privileged part of the army. However, the context suggests that in 325 the comitatenses were still soldiers currently serving directly under the emperor's command.
Ammianus Marcellinus, a military commander and chronicler of the second half of the fourth century AD, also mentions the Comitatenses as troops under the personal command of the emperor and directly attached to him.
Over time, when the emperors ceased to personally participate in military campaigns and increasingly entrusted the leadership of campaigns to their military leaders, the term "komitatens" ceased to refer to the personal troops of the emperors. By the beginning of the fifth century, the term Comitatensis had become simply an honorary title awarded to distinguished military units that did not belong to the emperor's personal guard. This understanding of the term would continue until the fall of the Western Roman Empire in 476.
In the IV century, for example, Legio XIIII Comitatensis served on the Danube as part of the ripenses-a river flotilla, infantry and coastal border forces, which clearly allows us to attribute this legion of comitatenses to limitans. Thus, the clear division of the late Roman army into stationary limitans and mobile field armies of comitatenses, adopted in the time of Delbruck, now seems to be a simplification that may not fully reflect the real picture.
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