À propos de la création des magistri militum par Constantin Ier

This paper offers a reexamination of Constantine’s creation of the magistri militum : having increased the prefects’ numbers, the emperor transferred their military powers (management of troops, discipline and eventually effective command) to the magistri militum. He intended not to strip the prefects of power, but to relieve them, in a difficult context (campaigns on the Danube, numerous federates to incorporate to the army, growing complexity of units denomination). Consistent evidences allow to narrow the chronological range of this change, around 328 AD.