The praetorian guard is a greatly maligned institution. In popular culture the guard is remembered as an instrument of tyranny, adept at both creating and removing emperors, whose loyalty could be purchased by the highest bidder. As B.’s engaging volume demonstrates, this reputation is ill deserved. A number of studies on the guard have been published since the fundamental works of Durry and Passerini (M. Durry, Les Cohortes Prétoriennes [1938]; A. Passerini, Le Coortie Pretorie [1939]). B.’s account is the first comprehensive overview published in English in recent years and is designed to be accessible to both a specialist and a general readership. The subtitle of the volume could be misconstrued, as the praetorians did not offer the advanced fighting skills exhibited by special forces in the modern world. Although they did occasionally serve on campaign, notably under Trajan and Marcus Aurelius, the praetorians could never surpass the martial abilities of the provincial armies. Yet the guard can be classed as an elite unit on account of their privileged levels of pay and length of service in comparison with the legions. The pleasures of military service in the imperial capital may also have been attractive although, as B. notes, unsanitary conditions in Rome could have had an adverse impact on their health.
The primary role of the guard was to safeguard the lives of the emperor and, if required, his immediate family. Their success in this regard is often overlooked. Under the early empire, imperial assassinations were usually conducted by individuals whose pre-existing relationships with the emperor allowed them to circumvent the security apparatus. Random attacks by lone assassins, as feared by modern intelligence services, were rare. B. argues convincingly that the function of the praetorians exceeded their imperial protection duties. During the Republican period, the cohors praetoria could potentially have either a military or administrative role. This may be reflected in the range of duties assumed by the imperial guard. Throughout its existence, the guard acted as an instrument of the state security apparatus. In this capacity, praetorians made arrests and conducted executions. Overt surveillance operations pressurised enemies of the regime to commit suicide, thereby ridding the emperor of direct association with their executions. Thus the persistent praetorian presence around Gnaeus Calpurnius Piso must inevitably have contributed to his death (Tac. Ann. 3.14.5). The guard also played a significant role in providing security at public events in Rome, particularly those attended by the emperor. Their presence in such circumstances demonstrated the willingness of the emperor to assure the safety of the populace. B. highlights an extensive range of evidence which indicates that the guard regularly fought fires in the capital. An inscription from Ostia commemorates a praetorian who perished fighting a blaze there (ILS 9494).
The billeting of the guard in Rome created a paradox for the emperor. As the closest military presence, they acted as his most basic means of defence and, potentially, his most immediate threat. Thus the command of the guard was a highly sensitive position. The collegiate nature of the praetorian prefecture and its association with the equestrian order were designed to limit the threat posed by a subversive individual. Some emperors took extraordinary steps to assure their loyalty. Commodus changed his prefects with alarming frequency; in one case the post was allegedly held for a mere six hours (Hist. Aug. Comm. 6.6–7). Of the prefects whose loyalty was questionable, Casperius Aelianus is the most intriguing. He first served as prefect under Domitian and returned to the role during the reign of Nerva, probably as a compromise to praetorians angered by the assassination of the last Flavian emperor (Dio Cass. 68.3.3). Indeed, Aurelius Victor records that the Senate came to an arrangement with the guard in order to appease them (Aur. Vict. Caes. 11). Aelianus led the praetorians in forcing the execution of high profile individuals involved in the assassination of Domitian against the wishes of the emperor (Dio Cass. 68.3.2). Aelianus’ influence over the guard was only halted by the intervention of Trajan, who is widely assumed have executed the renegade prefect and his fellow conspirators (Dio Cass. 68.3.4). B. notes that Dio's language is ambiguous on this point and it is possible that Trajan merely allowed the prefect to retire into obscurity. In B.’s reconstruction, this clemency was due to an unspecified role which Aelianus played in bringing Trajan to power. Allusions to a military conspiracy behind Trajan's accession have been commonplace in modern scholarship (see R. Syme, Tacitus [1958], p. 35; A. Berriman and M. Todd, Historia 50.3 [2001], 312–31). Yet there is an alternative possibility concerning Aelianus’ motivations in defying Nerva. His links to the Flavian dynasty may have been far deeper than serving Domitian as prefect. One source claims that Aelianus served as tribune under Vespasian in Judaea (Phil. VA 7.18; see R. Syme, Tacitus [1958], p. 35 n. 4). He may even have previously served as a centurion under Domitius Corbulo, whose legions are known to have provided a number of active supporters for the Flavian bid for power (Tac. Ann. 15.5.2; see F.J. Vervaet, Historia [2003], pp. 436–64). It is therefore possible that Aelianus’ motives were dictated not by his loyalties to Trajan but rather his allegiance to the Flavian dynasty and his genuine desire to avenge the fallen emperor. In this regard, Aelianus may have expected clemency from Trajan, as the latter had also proved himself to be loyal to Domitian (Plin. Pan. 14.3–5). Regardless of whether Aelianus was executed or retired, Trajan had no option but to remove a prefect who had proved willing to disregard imperial authority.
The perennial fascination for the praetorian guard among scholars and the general public alike will furnish this volume with a wide readership. B. provides a comprehensive overview of the guard which is not limited to their appearance in the historical record, but also encompasses their depiction on contemporary artworks and the archaeology of the Castra Praetoria. The wealth of notes supporting the text will be a welcome resource for an academic audience. This volume should be particularly recommended for students seeking a deeper understanding of the role of the guard in imperial politics and society.
