Distinctive Praetorian Insignia

The Praetorian Guard did utilize distinctive symbolism to set themselves apart from legionary troops.  The most basic was their wear of the classical toga while on duty in the imperial palace.  Praetorian standard-bearers (signiferi) wore lion-skins over their helmets instead of the legionary bearskins, while Praetorian standards (signa) differed noticeably from their legionary equivalents, incorporating images (imagines) of the emperor as well as crowns and other unit decorations for valor.

Other motifs common to Praetorian signa include moon and stars, guardian spirits (genii), scorpions, and eagles.  The occurrence of eagles on  Praetorian signa indicates that the aquiline symbol was not necessarily limited to legionary use (e.g., the aquila eagle-standard that was a legion’s focal totem).

The scorpion was the natal emblem of the Praetorian Guard, representing Scorpio, the astrological symbol under which the Emperor Tiberius was born.  Although the Praetorians were formally organized by Augustus, his successor Tiberius was called the - second founder - of the Guard.

Tiberius, at the urging of his calculating Prefect Sejanus, recalled all the Praetorian cohorts from their dispersed postings throughout Italy.  On the outskirts of Rome, Tiberius ordered the construction of a great walled camp, the Castra Praetoria, where the entire Guard would be billeted.  These major changes greatly concentrated the power of the Praetorian Guard, a fact that did not long escape their notice.

In gratitude to Tiberius, the Guard adopted his birth-sign, Scorpio, as their own emblem since they were 'reborn' under his rule.  The scorpion seems to have been the most distinguishing mark of the Praetorians upon the field of battle, for it decorated their standards, shields, and even appeared on helmets and other privately procured equipment.  A scorpion symbol is also found on a coin minted by Caligula to honor his Praetorians.

Ironically, the Praetorians lived up to their birth-sign’s vicious reputation, delivering a treacherous sting to an unwary or incompetent Emperor.

Service and Careers

In Augustus' time, an enlistee in the Guard signed on for a service term of 12 years.  By 5 CE, Augustus had lengthened the term to 16 years. Most volunteers -- and all Guardsmen were volunteers, since vacancies in the Guard were much sought after -- were between the ages of 15 and 32 years.  (Contrastingly, legionary recruits were generally 18-23 years old; the more strenuous service conditions of the legions perhaps account for the difference.)

During his 16-year service, a Guardsman could expect to remain primarily in the city of Rome -- a far more pleasing prospect to an enlistee than the 20-year term of the legionary recruit who would be soldiering on the distant frontiers of the Empire.  For this reason, service in the Praetorian Guard remained a popular option for Italian youth, even after Italian enlistment in the legions began to decline.

Originally, Augustus formed his Guard from a cadre of faithful veterans, but in the subsequent years of the 1st and 2nd c. CE, vacancies were filled from the civilian populace of Rome.  By the era of Septimius Severus, more Praetorian billets were being filled by military personnel transferred from the Vigiles, the Cohortes Urbanae, or the legions -- these men having proved their worth after a few years' good service.

Once in the Guard, a soldier who performed well might be offered special positions with increased pay and benefits, or be offered a posting to the Guard cavalry.  Epigraphic evidence suggests that Guard cavalrymen normally had five years' prior service in the Praetorian infantry arm.

From the time of Augustus, Praetorians like other soldiers were forbidden to contract legal marriages, although many men did in fact contrive to form habitual relationships with women that were marriages in all but name.

Brian Dobson has estimated that seven centurionate positions became vacant each year in Rome amongst the Praetorians, Urban Cohorts, and Vigiles.  Of 90 legionary centurionates being made vacant annually through discharge and deaths, perhaps 17 might have been filled from the corps of  Praetorians.  The financial attraction of higher rank clearly provided an incentive to Praetorian Guardsmen to be promoted to the commissioned ranks of the centurionate.

It was rare for Praetorian centurions to be selected from sources outside the Guard.  The most common route to the Praetorian centurionate was for a Guardsman to serve his 16 years, be retained as an evocatus (time-expired reservist), then be offered centurion positions first in the Vigiles, then the Urban Cohorts, finally returning to the Guard.

The singular post of primus pilus (chief centurion of a legion) ushered its holder into the ranks of the equestrian order.  As an equestrian, the primus pilus could aspire to a tribunate in the Vigiles, Urban Cohorts, or Praetorian Guard.  Many Praetorian tribunes were primipilares who had previously held tribunates of the Vigiles or Urbani.  The next step for such men would be primus pilus bis or iterum, and thereafter for a tiny few, the possibility of equestrian procuratorships or prefectures.