''Protector Augusti Nostri'' (''lit'' 'Protector of Our Augustus') was a title given to individual officers of the

Roman army The Roman army (Latin: ) was the armed forces deployed by the Romans throughout the duration of Ancient Rome, from the Roman Kingdom (c. 500 BC) to the Roman Republic (500–31 BC) and the Roman Empire (31 BC–395 AD), and its medieval contin ...

as a mark of their devotion to and approval by the Emperor himself. The term first appears with this meaning in the joint-reign of Valerian and

Gallienus Publius Licinius Egnatius Gallienus (; c. 218 – September 268) was Roman emperor with his father Valerian from 253 to 260 and alone from 260 to 268. He ruled during the Crisis of the Third Century that nearly caused the collapse of the empi ...

Lucius Petronius Taurus Volusianus Lucius Petronius Taurus Volusianus (died c.286 AD) was a Roman citizen, apparently of equestrian origins, whose career in the Imperial Service in the mid-Third Century AD carried him from a relatively modest station in life to the highest public ...

was the first recorded ''Protector'' appointed by Gallienus.

Imperial Guards of Gallienus

The use of the title ''protector'' in the sense of a 'bodyguard of a Great Man' long preceded the appointment of Volusianus. In addition, the title was not only bestowed by Emperors. However, it does seem to be the case that Gallienus was the originator of the ''Protectores Augusti Nostri''. 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 Ingenuus was a Roman military commander, the imperial legate in Pannonia, who became a usurper to the throne of the emperor Gallienus when he led a brief and unsuccessful revolt in the year 260. Appointed by Gallienus himself,Leadbetter, ww.rom ...

and were marked out for accelerated promotion under his patronage. Its utility as an instrument for adding lustre to newly equestrianised military career structure soon became apparent. The first recipients were Tribunes of the Praetorian Cohorts – such as Volusianus – and equestrian commanders of legions such as

Publius Aelius Aelianus Publius Aelianus Aelianus was a senior officer in the Imperial Roman army in the mid-Third Century AD who rose from relatively lowly origins to become the prefect of a legion under the Emperor Gallienus He was one of the earliest beneficiaries of ...

. So far as is known it was never bestowed on any officer of senatorial rank – senators were effectively excluded from service in the army soon after the first ''protectores'' appeared. Toward the end of Gallienus's reign centurions too were given this title. By this time it was used exclusively to distinguish officers who had served in units associated with Gallienus's imperial field army, the ''

comitatus ''Comitatus'' was in ancient times the Latin term for an armed escort or retinue. The term is used especially in the context of Germanic warrior culture for a warband tied to a leader by an oath of fealty and describes the relations between a lo ...

'' Collectively, the first ''protectores'' might be more properly defined as a ''collegio'' (i.e., a guild) rather than a military unit serving a specific military purpose. There is contemporary reference to a ''Princeps Protectorum'', but it is likely that this officer's functions related to ceremonial than to leadership in battle.One of the first known ''princeps protectorum'' was Traianus Mucianus (see Mihailov ''op.cit.''). As far as can be determined that officer had no substantive office when he held the title, and Christol (''op.cit.'') infers that his was a purely nominal posting while he waited for promotion to the rank of ''

primus pilus The ''primus pilus'' or ''primipilus'' was the senior centurion of the first cohort in a Roman legion, a formation of five double-strength centuries of 160 men, was called the ''primus pilus''; he was a career soldier and advisor to the le ...

''. Holding commissioned rank in a unit attached to the ''comitatus'' seems to have been the ''sine qua non'' of admission to the body. These were men noticed by the Emperor likely to receive accelerated promotion in his service. 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 promote ambition among the officer ''cadres'' of provincial garrisons, which would serve the same purpose.

After Gallienus

After the death of Gallienus the ''protectores'' seem to have evolved into a military unit. The future Emperor Diocletian made his successful bid for the purple in 284 AD as commander of this body, challenging the Praetorian Prefect

Aper Aper may refer to: People * Aper (grammarian), 1st century Greek grammarian * Marcus Aper, 1st century Roman orator * Trosius Aper, 2nd century Roman grammarian and Latin tutor to Marcus Aurelius * Gaius Septimius Severus Aper (ca. 175–211/2 ...

whose power-base was the

Praetorian Guard The Praetorian Guard (Latin: ''cohortēs praetōriae'') was a unit of the Imperial Roman army that served as personal bodyguards and intelligence agents for the Roman emperors. During the Roman Republic, the Praetorian Guard were an escort fo ...

. However, membership of the corps still seems to have continued to be reserved for young soldiers marked out for rapid promotion.

Constantine I Constantine I ( , ; la, Flavius Valerius Constantinus, ; ; 27 February 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337, the first one to Constantine the Great and Christianity, convert to Christiani ...

was probably a member at the court of

Galerius Gaius Galerius Valerius Maximianus (; 258 – May 311) was Roman emperor from 305 to 311. During his reign he campaigned, aided by Diocletian, against the Sasanian Empire, sacking their capital Ctesiphon in 299. He also campaigned across th ...

and

Ammianus Marcellinus Ammianus Marcellinus (occasionally anglicised as Ammian) (born , died 400) was a Roman soldier and historian who wrote the penultimate major historical account surviving from antiquity (preceding Procopius). His work, known as the ''Res Gestae ...

got his first step on the ladder of promotion in this capacity. Thus by that time it had acquired some of the characteristics of an Imperial staff college.

References

{{cite book , title=The Roman Empire from Severus to Constantine , last=Southern , first=Pat , year=2001 , publisher=Routledge , location=London Military ranks of ancient Rome Ancient Roman titles