Centurions 4th Century AD

[Urselius]

Vegetius linked the terms centenarius and centurio, but he is not always reliable. Possibly, a duality of ranks reflected the move from the traditional Roman unit composition to a decimal (multiple of 10 system), such as was common in later Byzantine units. As has been mentioned new types of unit would be the first to use a new rank system, with old-style units possibly retaining old-style ranks. Steppe nomads often used a decimal system of organisation for warbands, possibly relevant here.