The primary role of the Praetorian Guard was political, not military. Stationed in Rome to provide an escort for the emperors, this political role (and the influence, benefits, and prestige that existed because of it) far outstripped their military importance. The Guard was never intended to be an elite reserve. While the Guard proved a competent and efficient force when on campaign, there is no indication that their privileged status made them better soldiers.

During the first century B.C., the term cohors praetoria came to refer to bodyguards of Roman commanders during the civil wars that saw the death of the republican system and the rise of Octavian (who for clarity’s sake I will refer to as Augustus). Augustus retained nine praetorian cohorts following his victory in the civil wars. Three of these cohorts were stationed in Rome, where they provided security for Augustus and his residence. Tiberius consolidated the Guard in Rome with the construction of a permanent barracks (the Castra Praetoria). The number, size, and organization of the Guard fluctuated, being finalized by Domitian to ten, 800 men cohorts jointly commanded by two prefects of equestrian rank.

From its inception, the Guard enjoyed a privileged position. Praetorians served initially for only twelve years. While this was raised to sixteen in 5 A.D., it remained less than the twenty years served by legionaries (and the twenty-five served by auxiliaries). Service in the Guard often brought the possibility of promotion to the legions in senior under-officer grades. Praetorians were paid roughly triple the anual salary of legionaries, and received a bonus of 5,000 denarii upon discharge, compared with 3,000 for legionaries. As the emperor’s personal guards, the Praetorians were lavished with donatives (special cash gifts), as the immediate security of an emperor and his family depended upon the loyalty of the Guard. Emperors were frequently proclaimed by the Guard in the Castra Praetoria, a ceremony commonly stamped upon imperial coinage. While the legions rapidly provincialized over the course of the first century A.D., the Guard was comprised almost exclusively of Italians. Service in the Guard was far more attractive for Italians, not only for the financial benefits, but also because of the “lifestyle” benefits of being stationed in Rome, especially the lack of the dangers of discomforts of the frontier. The high pay, shorter service, and prestige came not from special training or equipment (and certainly not out of a sense of Italian solidarity), but from their role as the sovereign’s guards, and their position at the center of imperial politics. The Guard could make and unmake emperors; the discrepancy in benefits attests to the importance emperors placed on their loyalty.

Yet we should not view the Guard as a mere parade-ground unit. Praetorians did not wear (as has often been suggested, based upon uncritical analysis of iconographic evidence) ceremonial, archaic armor. Rather, the Guard appears to have been equipped in a manner similar to legionaries. The Praetorians distinguished themselves with unique shield blazons and banners, rather than with special equipment. As they were equipped and fought like legionaries, Praetorians would have trained in a similar manner, with an emphasis on drill, unit cohesion, and unit maneuver. No evidence exists of specialized training for Praetorians.

Various emperors employed the Guard on campaign, most especially Trajan and Marcus Aurelius. The role of the Guard in Trajan’s Dacian Wars of 101-102 and 105-106 A.D. is prominently recorded on his Column in Rome. While their specific role on the battlefield is unclear, the Praetorians do not appear to have been a frontline unit, with most combat being conducted by frontier legionaries and auxiliaries. That said, the Guard appears to have acquitted itself well in campaigns during the first and second centuries A.D., with no sources explicitly criticizing their performance.

The main role of the Praetorian Guard was not as a military elite, but rather as the emperor’s guards, whose position at the heart of power brought huge political influence. From its inception, emperors lavished the Guard with prestige and benefits, knowing its loyalty was essential to their position on the throne. Yet on campaign, the Guard was a competent force, able to take the field beside their frontier counterparts. While not elite because of any specialized training, they could, when well officered, perform effectively in combat. Indeed, it is mostly for political reasons, rather than military, that the Guard will be slowly marginalized over the course of the third century, as well as its abolition by Constantine in 312 A.D.