If you study the history of ancient Rome, you will likely have heard of the Praetorian Guard. This was an elite group of Roman citizens and others that had been handpicked to act as body guards for the Emperor and other important figures. Members of the Guard also acted as prison guards and carried out various tasks that were considered to be too sensitive to entrust to common soldiers.
But who were they really? In their earliest days, it is true that they carried out the roles for which they had been chosen. In later days, however, members of the Praetorian Guard became more powerful in their own right and began to act in ways that influenced the political structure of Rome.
Many of the Caesars had a group of personal bodyguards who were chosen for their skill and their loyalty. The Caesars who had such a bodyguard included Julius Caesar, Octavian Augustus and Sertorius. Not all of the personal bodyguards were Romans. Some Caesars chose units of Basque soldiers and others chose to have legions of German troops protecting them. However, it was not until Octavian Augustus took command in 27 BCE that the Guard was formally recruited as a tool that could be used to influence politics as well as the outcome of a battle.
The Guard started out as a relatively small unit. In its earliest days there were only nine cohorts of men. Each cohort held 500 men. Over time, the size of each cohort doubled although only three of the cohorts were on active duty in the capital. There were also cavalry units that were later added to the Guard. These patrolled the palace and other major Roman buildings. At this time, because there did not seem to be much political threat from the Guard most Romans hardly even took notice of their presence.
Things began to change in 23 CE. The prefect at the time, Lucius Aelius Sejanus, was a man with ambition. Due to his urging the Emperor Tiberius decided to build a fort specifically to house the Guard. This structure became known as the Castra Praetoria, which means the fort of the Praetorians. They now were stationed closer to Rome and could now begin to control the political climate in the city much more easily.
The Praetorians were known for their assassination of several Emperors including Caligula (who was killed in 41 CE) and Galba (killed in 69 CE). They also were the force behind Claudius taking the throne after Caligula’s assassination. Emperors knew that without the support of the Praetorian Guard their reign was likely to be a short one.
Later Emperors were careful to limit the size and influence of the Guard. The number of cohorts was reduced back to nine and one clever emperor, Vespasian, made sure to appoint his son as the Prefect or leader of the Guard. In 284 CE, the Guard was no longer involved in palace life. The emperor at the time, Diocletian, no longer lived in Rome. He replaced the Praetorians with two other units that would act as his personal bodyguards.
The Guard was ultimately disbanded in 312 CE by Constantine the Great. He sent the soldiers to various corners of the empire and even demolished their fortress. Their influence on Rome was finally at an end.