Protectores Augusti Nostri

"Protector Augusti Nostri" ("lit" 'Protector of Our Augustuses') was a title given to individual officers of the Roman Army. The term first appears in the joint-reign of Valerian and Gallienus (who were the 'Augusti' referred to). The term "Protector Divini Lateris" (i.e. 'Protectors of the Sacred Side') also appears around this time. L. Petronius Taurus Volusianus was the first recorded Protector.

It seems that, when it was first bestowed, this title signified an honour conferred on rather than a function carried out by the recipient. It seems to have been granted to officers who had distinguished themselves serving directly under Gallienus in his wars against barbarian invaders of the Balkan and German provinces and Italy and would-be usurpers in those regions such as Ingenuus and were marked out for accelerated promotion under his patronage. The first recipients were Tribunes of the Praetorian Cohorts - such as Volusianus - or equestrian commanders of legions. (So far as is known it was never bestowed on any officer of senatorial rank - senators were excluded from service in the army soon after the first "protectores" appeared). Collectively, therefor, at first the Protectors were a guild or an order rather than a defined military unit under a single command. There is reference to a "Princeps Protectorum", but it is likely that this officer's functions related to ceremonial than to leadership in battle. Membership of the "corps" was not inconsistent with appointments to regular military command any more than membership of the Order of the Garter is a bar to promotion in the modern British Army - on the contrary.

The purpose of the "Protectores" at this time seems to have been two-fold: (i)to encourage a personal loyalty to the "Augusti" (particularly Gallienus: there is no reason to suppose that Valerian had any real interest in this innovation) among the most energetic and charismatic officers of the Imperial Field Army and thus combat the spirit of military dissent that was tearing the Empire apart at this time; (ii) to demonstrate to the provincial garrisons that their Emperor valued them which would, of course, serve the same purpose.

After the death of Gallienus the "Protectores" seem to have taken on more of the characteristics of a military unit. It was as commander of this body that the future Emperor Diocletian made his successful bid for the purple in 284 AD, challenging the Praetorian Prefect Aper whose power-base was the Praetorian Guard. However, membership of the corps still seems to have continued to be reserved for young soldiers marked out for rapid promotion as the career. Constantine I was probably a member at the court of Galerius and Ammianus Marcellinus got his first step on the ladder of promotion in this capacity. Thus by that time day it had acquired some of the characteristics of an Imperial staff college.

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