thumb|260px|The [[Praetorians Relief with an aquila grasping a thunderbolt through its claws, in reference to the Roman form of Jupiter.]]
The Praetorian Guard () was the imperial guard of the Imperial Roman army that served various roles for the Roman emperor including being a bodyguard unit, counterintelligence, crowd control and gathering military intelligence.
During the Roman Republic, the Praetorian Guards were escorts for high-ranking political officials and were bodyguards for the senior officers of the Roman legions. In 27 BC, after Rome's transition from republic to empire, the first emperor of Rome, Augustus, designated the Praetorians as his personal security escort. For three centuries, the guards of the Roman emperor were also known for their palace intrigues; the Praetorians could overthrow an emperor and then proclaim his successor as the new caesar of Rome. In AD 312, Constantine the Great disbanded the Praetorian Guard and destroyed their barracks at the Castra Praetoria.
In the Roman Republic
The Praetorian Guard originated as bodyguards for Roman generals in the period of the Roman Republic (509–27 BC). During the longer campaigns of the Roman army of the late Republic, the personal bodyguard unit was the norm for a commander in the field. At camp, the , a cohort of praetorians guarding the commander, was posted near the , the tent of the commander.
The first historical record of the praetorians is as bodyguards for the Scipio family, ca. 275 BC. Generals with (command authority of an army) also held public office, either as a magistrate or as a promagistrate; each was provided with lictors to protect the person of the office-holder. In practice, the offices of Roman consul and of proconsul each had twelve lictors, whilst the offices of praetor and of propraetor each had six lictors. In the absence of an assigned, permanent personal bodyguard, senior field officers safeguarded themselves with temporary bodyguard units of selected soldiers. In Hispania Citerior, during the Siege of Numantia (134–133 BC), General Scipio Aemilianus safeguarded himself with a troop of 500 soldiers against the sorties of siege warfare aimed at killing Roman field commanders.
At the end of 40 BC, two of the three co-rulers who were the Second Triumvirate, Octavian and Mark Antony, had Praetorian Guards. Octavian installed his praetorians within the , the religious and legal boundary of Rome; this was the first occasion when troops were permanently garrisoned in Rome proper. In the Orient, Antony commanded three cohorts; in 32 BC, Antony issued coins honouring his Praetorian Guard. According to the historian Orosius, Octavian commanded five cohorts at the Battle of Actium in 31 BC; in the aftermath of Roman civil war, the victorious Octavian then merged his forces with the forces of Antony as symbolic of their political reunification. At this point the force numbered at most 5 400 men organised into nine cohorts. Later, as Augustus, the first Roman emperor (27 BC–AD 14), Octavian retained the Praetorians as his imperial bodyguard.
Under the empire
The legionaries known as the Praetorian Guard were first hand-picked veterans of the Roman army who served as bodyguards to the emperor. First established by Augustus, members of the Guard accompanied him on active campaign, protecting the civic administrations and rule of law imposed by the Senate and the emperor. The Praetorian Guard was ultimately dissolved by Emperor Constantine I in the early 4th century. They were distinct from the Imperial German Bodyguard which provided close personal protection for the early Roman emperors. They benefited from several advantages via their close proximity with the emperor: the Praetorians were the only ones admitted while bearing arms in the center of sacred Rome, the .
Their mandatory service was shorter in duration, for instance: 12 years with the Praetorians instead of 16 years in the legions starting year 13 BC, then carried to, respectively, 16 to 20 years in year 5 BC according to Tacitus. Their pay was higher than that of a legionary. Under Nero, the pay of a Praetorian was three and a half times that of a legionary, augmented by prime additions of , granted by each new emperor. This additional pay was the equivalent of several years of pay and was often repeated at important events of the empire or events that touched the imperial family: birthdays, births and marriages. Major monetary distributions or food subsidies renewed and compensated the fidelity of the Praetorians following each failed particular attempted plot (such as that of Messalina against Claudius in AD 48 or Piso against Nero in AD 65). The Praetorians received substantially higher pay than other Roman soldiers in any of the legions, on a system known as , or by pay-and-a-half. So if the legionaries received 250 denarii, the guards received 375 per annum. Domitian and Septimius Severus increased the (payment) to 1,500 denarii per year, distributed in January, May and September.
Feared and dreaded by the population and by the Roman Senate, the Praetorians received no sympathy from the Roman people. A famous poem by Juvenal recalls the nail left in his foot by the sandal of a Praetorian rushing by him. "Praetorian" has a pejorative sense in French, recalling the often troubling role of the Praetorian of antiquity.
History
In ancient Rome, praetors were either civic or military leaders. The praetorians were initially elite guards for military praetors, under the republic. The early Praetorian Guard was very different from what it became later, as a vital force in the power politics of Rome. While Augustus understood the need to have a protector in the maelstrom of Rome, he was careful to uphold the Republican veneer of his regime. Thus, he allowed only nine cohorts to be formed, each originally consisting of 500 men. He then increased them to 1,000 men each, allowing three units to be on duty at any given time in the capital. A small number of detached cavalry units () of 30 men each were also organized. While they patrolled inconspicuously in the palace and major buildings, the others were stationed in the towns surrounding Rome. This system was not radically changed with the appointment by Augustus in 2 BC of two Praetorian prefects, Quintus Ostorius Scapula and Publius Salvius Aper, although organization and command were enhanced. Tacitus reports that the number of cohorts was increased to twelve from nine in AD 47. In AD 69 it was briefly increased to sixteen cohorts by Vitellius, but Vespasian quickly reduced it again to nine.
Under the Julio-Claudian dynasty
In Rome, the guards' principal duty was to mount the Guard at the house of Augustus on the Palatine, where the centuries and the turmae of the cohort in service mounted the guard outside the emperor's palace (the interior guard of the palace was mounted by the Imperial German Bodyguard, often also referred to as Batavi, and the Augusti, a sort of military police which were found in the general staff headquarters of the Roman Army). Every afternoon, the would receive the password from the emperor personally. The command of this cohort was assumed directly by the emperor and not by the Praetorian prefect. After the construction of the Praetorian camp in 23 BC, another similar serving tribune was placed in the Praetorian camp. The guards' functions included, among many, escorting the emperor and the members of the imperial family and, if necessary, to act as a sort of riot police. Certain Empresses exclusively commanded their own Praetorian Guard.
According to Tacitus, in the year 23 BC, there were nine Praetorian cohorts (4,500 men, the equivalent of a legion) to maintain peace in Italy; three were stationed in Rome, and the others nearby.
According to Boris Rankov in 1994, an inscription recently discovered suggested that, towards the end of the reign of Augustus, the number of cohorts increased to 12 during a brief period.
Despite their political power, the Praetorian Guard had no formal role in governing the Roman Empire. Often after an outrageous act of violence, revenge by the new ruler was forthcoming. In 193, Didius Julianus purchased the Empire from the Guard for a vast sum, when the Guard auctioned it off after killing Pertinax. Later that year Septimius Severus marched into Rome, disbanded the Guard and started a new formation from his own Pannonian legions. Unruly mobs in Rome often fought with the Praetorians in vicious street battles during Maximinus Thrax's reign.
In 271, Aurelian sailed east to destroy the power of Palmyra, Syria, with a force of legionary detachments, Praetorian cohorts, and other cavalry units, and easily defeated the Palmyrenes. This led to the orthodox view that Diocletian and his colleagues evolved the (the field escort of the emperors). The included field units that used a selection process and command structure modeled after the old Praetorian cohorts, but it was not of uniform composition and was much larger than a Praetorian cohort.
Organization
Leadership
Starting in the year 2 BC, the Praetorian prefect was the commanding officer of the Praetorian Guard (previously each cohort was independent and under the orders of a tribune of equestrian rank). This role (chief of all troops stationed in Rome), was in practice a key position of the Roman polity.
From Vespasian onwards the Praetorian prefecture was always held by an equestrian of the order. (Equestrians were traditionally that class of citizens who could equip themselves to serve in the Roman Army on horseback).
From the year 2 BC, the cohorts were under the control of two prefectures; however cohorts continued to be organized independently, each commanded by a tribune. Tribunes had as immediate subordinates ordinary Centurions, all of equal rank except for the , the first and prime of all centurions of the Praetorian Cohorts, who commanded also the 300 , and with the exception of his second, the princeps castrorum.
In order not to alienate the population of Rome, while conserving Republican civilian traditions, the Praetorians did not wear their armor while in the heart of the city. Instead they often wore a formal toga, which distinguished them from civilians but remained in a respectable civilian attire, the mark of a Roman citizen. Augustus, conscious of risking the only military force present in the city, often avoided concentrating them and imposed this dress code.
From the reign of Tiberius, their camp was situated on the Quirinal Hill, outside Rome. In 26 AD, Sejanus, Praetorian prefect, and the favorite of emperor Tiberius, united the Urban Cohorts with nine Praetorian Cohorts, dispersed at that time throughout Italy, in one large camp situated beyond the Servian Wall, on the Esquiline Hill, the .
For the 2nd century, calculations from lists of significant demobilisations suggest an increase in size to nearly 1,500 men per cohort (perhaps a doubling of 800 (since Vespasian), probably organized in 20 centuries) under Commodus in year (187–188) or under Septimius Severus (193–211), which matches the probable numbers of effectives for Urban Cohorts during the time of Cassius Dio. These figures suggest an overall size for the Guard of 4,500–6,000 men under Augustus, 12,800 under Vitellius, 7,200 under Vespasian, 8,000 from Domitian until Commodus or Septimius Severus, and 15,000 later on.
At the beginning of the 2nd century, Italians made up 89% of the Praetorian Guard. Under Septimius Severus, recruitment evolved to authorize the inclusion of legionaries of the Roman army, as well as of the battle hardened Army of the Danube. Severus stationed his supporters with him in Rome, and the Praetorian Guards remained loyal to his choices.
Praetorian Cavalry
Initially each cohort included, as for a Roman legion, a cavalry detachment; this should not be confused with the who appeared under the emperor Trajan. The Praetorian could become a cavalryman () after almost five years service in the infantry. These Praetorians remained listed in their Centuries of origin, but operated in a of 30 men each commanded by an .
There was probably one of cavalry for two centuries of infantry.]]
Originally, the Praetorian Guard was recruited from the populations of central Italy (Etruria, Umbria and Latium according to Tacitus). Recruits were between 15 and 32 years of age, compared to legionary recruits who ranged from 18 to 23 years of age. According to Cassius Dio, during the first two centuries AD and before the reform of Septimius Severus, the Praetorians were exclusively limited to Italy, Spain (Roman province), Macedonia and Noricum (current Austria and Slovenia).
Under the reign of Vitellius, and starting from Septimius Severus, men were transferred from the Urban Vigiles, Urban cohorts, and the various legions. This recent method and manner of recruitment at the corps of the legions became the normal procedure to recruit in the 3rd century after Septimius Severus dealt with the undisciplined Praetorians who assassinated Pertinax in 193, and replaced them with men from his own Danube legions.
At that time, the Praetorians represented the best soldiers from the legions (principally from Illyria). They were a group of elite of soldiers starting from the 3rd century, and not a category of socially privileged soldiers (such as the Italians at the time of Augustus). The Italians formed the base of the recruitment of the , a new legion created and stationed in Italy.
To be admitted to the Guard, a man had to be in good physical condition, have a good moral character, and come from a respectable family. In addition, he had to make use of all sorts of patronages available to him in order to obtain letters of recommendations from important leading figures in society. Once past the recruitment procedure he was designated as , and assigned as a (soldier) to one of the centuries of a cohort. After two years, if he attracted the attention of his superiors by influence or merit, he could attain the post of (similar to corporal), perhaps as a (junior chief) at general headquarters or as a technician. This promotion exempted him from daily chores. After another two years he could be promoted to , with a double salary, in charge of delivering messages () or as an assistant centurion () or standard bearer () at the corps of the century; or, if literate and numerate, he could join the administrative staff of the prefect.
Only a few soldiers could attain the rank of ; however those who did, during the course of their service, were designated by the emperor. This designation allowed them to be promoted to technical administrative posts, or instructors in Rome, or to a century in a legion, and accordingly extend their career. Certain could at the end of their career be promoted to Centurion in the Guard; this would be the peak of his career. Anyone ambitious for further promotion would need to transfer to a legion.
The Military tribunes () at the head of the cohorts were Roman cavalrymen. In contrast to many superior cadres of the Army, who originated from the Equestrian Order, these tribunes started their career in the ranks of the Guard and were promoted from the ranks in the hierarchy. Next after becoming Centurions, they had to serve for a period of one year as superior centurions in one or several legions before achieving the status of (the highest ranked Centurion in a legion). Upon return to Rome, they occupied successively the positions of Tribunes of the Vigiles, Tribune of the Urban Cohort and finally Tribune of the Guard.
Other leading paths towards the tribunate were possible, including service entirely made in the legions, attaining the rank of before departing to Rome. Nevertheless, all tribunes were combat veterans with extensive military experience.