The Praetorian Guard is one of the most famous bodyguards in history. Founded by Augustus in 31 BC to guard the holder of the office known as Princeps or ‘First Citizen’ that would later be known by the military title ‘Emperor’, it’s access to the emperor, and position as the only armed force in Rome made it the most powerful group in the Roman Empire.
It was during the reign of Augustus’ successor Tiberius (AD 14 – AD 37) that the Guard truly came into its own as a power to make and unmake emperors. With the benefit of hindsight, it is arguable that the career of Sejanus foreshadowed the future. The head of the Praetorian Guard (AD 14 – AD 31), Sejanus allegedly plotted to overthrow Tiberius, and certainly monopolised power in Rome while Tiberius was in Capri. According to Josephus, Antonia, Sejanus’ mother in law who informed the emperor of the conspiracy, who responded by summoning Sejanus to a Senate meeting, officially to give him the powers of Tribune of the People. In reality, Tiberius had sent the Senate a letter ordering Sejanus’ arrest and execution.
The first time the Praetorian Guard effectively became the king makers of the Roman Empires was after the assassination of Tiberius’ successor, Caligula. According to Robin Lane Fox, this was the best opportunity in Roman history for the restoration of the Republic. The Praetorians however, famously found Caligula’s Uncle Claudius hiding behind a curtain, and proclaimed him emperor, forcing the Senate to accept him. Claudius paid the guards who had supported him handsomely, and the necessity of any Roman emperor to have the Praetorians supporting him was now well established.
The next time the Praetorian Guard played a decisive role in the imperial succession was after it deserted the Emperor Nero, and the Year of the Four Emperors began, (69 AD) however, when Nero’s first successor, Galba, failed to pay them enough, they assassinated him, and supported Otho, who gave them the right to choose their own prefects, in order to guarantee their loyalty. Ultimately this did not help them very much, and he was deposed by Vitellius.
Vitellius attempted to found his own Praetorian Guard, to avoid being dependent on the old one. However his new guard was of little help in dealing with Vespasian’s invasion, partly because Vespasian enlisted the former Praetorians. Vespasian (69 AD – 79 AD) was pragmatic enough to reduce the cohorts to nine, and appointed his son, the future emperor Titus (79 – 81 AD), as one of its commanders. Titus’ younger brother Domitian (81 – 96) was declared Emperor, and the plot to assassinate him involved members of the guard.
The five emperors (Nerva, Hadrian, Trajan, Antonius Pius and Marcus Aurelius) that followed Domitian are commonly known to history as the ‘Five Good Emperors’ and the palace intrigues and Praetorian partisanship that had characterised the Julio-Claudian and Flavian dynasties were for a time absent.
When Marcus Aurelius died in 180 AD, and his son Commodus became emperor, historians generally agree that the decline of the Roman Empire began. Edward Gibbon in particular considered the Praetorians to have played a role in the Roman Empire’s decline. An arguable example of this, is how during the rule of Commodus, the soldiers were given the right to hit anyone they encountered, and waves axes at people. Following Commodus’ assassination in 192 AD, his successor the emperor Pertinax was assassinated after a reign of only eighty-seven days, partly due to prohibiting the soldiers from being allowed to act as they liked. This was followed by one of the most remarkable methods of successions in history.
Didus Julianus (192-193), one of the two Consuls with Pertinax, went to the Praetorians’ camp, and offered them money in return for making him emperor. Pertinax’s father-in-law, the city prefect Sulpicianus was also present, and the two attempted to outbid each other, eventually, Sulpicianus offered 20,000 sesterces to every soldier, and Didus responded by offering 25,000, which won. He only ruled for 66 days however, and was overthrown in 193 AD by Septimius Severus. The Praetorians had become so accustomed to not actually fighting, that they offered little resistance.
Septimius Severus (193-211) replaced the Praetorian Guard with his own men. His son and successor Caracalla, (211-217), who despite his love for the army, was killed and replaced by the head of the Praetorian Guard, Marcus Opelius Macrinus (217-218), who alienated the soldiers due to his love of dressing in gold jewellery, leading to them deserting him, and supporting Elagabalus (218 AD – 222 AD), Elagabalus was in turn assassinated by the Praetorian Guard after he attempted to murder his cousin Severus Alexander who was popular with the soldiers.
Severus Alexander (222 AD – 235 AD), succeeded him, and despite having presided over one of the more effective Roman governments in the third century, with Domitius Ulpianus, the Praetorian prefect serving as de facto prime minister, the Praetorians killed him in 228 AD, and nearly killed the famous historian and then Consul Dio Cassius in 229 AD on the grounds that he was too severe. Severus Alexander saved Cassius’ life, but he himself was later assassinated by the army and was replaced by one of his commanders Maximinus Thrax (235 AD – 238 AD), beginning half a century of almost constant anarchy.
This only ended when the emperor Diocletian, (284 AD -305 AD) established the Tetrarchy, ending the Principate established by Augustus. By an interesting coincidence, he also effectively destroyed the Praetorian Guard as a force to make or break emperors. Augustus had created the guard to protect the emperor, and the imperial system that replaced the republic, instead, it ultimately contributed to it, and the empire’s downfall.