When you hear the phrase 10 times praetorian, you might picture a legion of disciplined soldiers marching in perfect formation. Yet the Praetorian Guard was far more than a ceremonial bodyguard; it was a political powerhouse that repeatedly reshaped the fate of Rome. From its inception under Augustus to its dramatic demise under Constantine, the guard’s actions—whether noble, treacherous, or downright brutal—left an indelible mark on the empire.
Why the Praetorian Guard Matters
The guard started as a collection of elite cohorts attached to magistrates, but it soon evolved into the emperor’s personal shield—sometimes a shield, sometimes a sword. Their loyalty could make or break an emperor, and their ambitions often drove Rome into civil war, intrigue, and even auction houses. Below, we count down the ten most pivotal moments when the Praetorian Guard changed the course of Roman history.
10 Augustus Founds The Praetorian Guard
Although the Praetorians are inseparably linked with the Roman emperor, their roots stretch back to the Republic, when elite units called Praetorian Cohorts served the magistrates known as praetors. During Caesar’s civil war, the number of these cohorts swelled, and both Augustus and Mark Antony maintained several of them.
When Augustus emerged as Rome’s first emperor, he consolidated the scattered cohorts into a single, permanent force: the Praetorian Guard. He had witnessed firsthand how a personal army could secure political power, thanks to Caesar’s own experience. Augustus stationed several cohorts in Rome while dispersing others throughout Italy, assigning them both protective duties for the emperor and policing functions for the capital.
From that moment on, the Guard’s influence surged, gradually becoming one of the most formidable institutions in the empire, capable of shaping policy, influencing succession, and even acting as a de‑facto police force within the city.
9 Assassination Of Pupienus And Balbinus
The year 238, famously known as the Year of the Six Emperors, was a whirlwind of power‑shifts, betrayals, and bloodshed. Within twelve months, six different men claimed the purple, and five of them met violent ends. The chaos began with Maximinus Thrax, the first “barracks emperor,” who rose to power in 235 thanks to the army’s backing, despite the Senate’s opposition.
By 238 a provincial governor named Gordian was urged to seize power, proclaiming himself emperor and naming his son, Gordian II, co‑emperor. Their short‑lived reign ended when Thrax’s forces defeated them, leading the Senate to appoint the elderly statesmen Pupienus and Balbinus as joint emperors. Meanwhile, riots erupted in Rome, and angry crowds turned to the Praetorian Guard—then aligned with Thrax’s supporters—to unleash their fury.
In a dramatic reversal, the Guard stormed the imperial palace, slaughtering both Pupienus and Balbinus. Simultaneously, Thrax’s own army turned on him, decapitating the tyrant and presenting his head to the capital as a gesture of contrition. The Senate then elevated Gordian III, ending the year’s carnage—at least for the moment.
8 The Guard Makes Galba Emperor And Then Murders Him
When Nero’s reign crumbled in 68 CE, the Senate sought a new ruler and found one in Galba, a seasoned general with a reputation for stern discipline. Yet the Praetorian Guard, ever opportunistic, saw a chance for profit. Their commander, Gaius Nymphidius Sabinus, publicly declared allegiance to Galba, prompting the troops to abandon Nero in exchange for a promised bounty.
According to Plutarch, the sum demanded was so astronomical that it would have required “ten thousand times more evils than those inflicted by Nero” to raise. The promised money never materialized, and after a mere seven months on the throne, the Guard turned on Galba, aligning themselves with Otho, who had his own designs on power.
In a swift and brutal coup, the Praetorians helped Otho seize the palace, and Galba’s own retinue, fearing the tide, switched sides and slayed their former leader. Only one soldier, Sempronius Densus, stood out for refusing to betray Galba, fighting to the death against his fellow Praetorians.
7 Macrinus’s Plot Against Caracalla
The office of Praetorian Prefect grew into a powerhouse, granting its holder unparalleled sway over imperial affairs. Yet ambition often overrode loyalty. Macrinus, who served as Prefect under Emperor Caracalla, saw an opening to usurp the throne.
Macrinus identified a disgruntled centurion named Martialis, who harbored deep resentment toward Caracalla after the emperor executed his brother and routinely insulted him. Exploiting Martialis’s hatred, Macrinus promised riches and favor in exchange for assassinating the emperor.
During a routine campaign, Caracalla stopped to relieve himself by the roadside. Seizing the moment, Martialis approached the emperor and plunged his dagger into Caracalla’s abdomen, killing him on the spot. The centurion was quickly captured and executed, while Macrinus, feigning sorrow, rallied support among the troops and proclaimed himself emperor within days.
6 Two Sets Of Guards Fight Against Each Other
After Otho’s three‑month reign ended in suicide, the throne passed to Vitellius, who promptly disbanded the existing Praetorian Guard and executed over a hundred of its members for their role in Galba’s murder. He then raised a new guard drawn from his Germanic troops, hoping to secure unwavering loyalty.
The Senate, however, backed Vespasian, a commander in the East, leading to a civil war. Unemployed former Praetorians joined Vespasian’s cause, and the two rival factions clashed at the Battle of Bedriacum. Led by Marcus Antonius Primus, Vespasian’s forces triumphed, decisively ending Vitellius’s brief rule.
In the aftermath, Vitellius’s remaining Praetorians tried to negotiate peace, only to be double‑crossed. When Vitellius attempted to flee, his own guards pretended to escort him safely, only to hand him over to Vespasian’s soldiers. He was dragged through the streets to the infamous Gemonian Stairs, where he met a grisly end—making him the sole Roman emperor to die on that very stairway.
5 Sejanus’s Rise To Power
While Augustus founded the Praetorian Guard, its real ascent began under his successor, Tiberius, thanks largely to the scheming of the ambitious prefect Sejanus. As Praetorian Prefect, Sejanus became one of the emperor’s closest confidants and, when Tiberius retreated to the island of Capri in his later years, Sejanus effectively ran Rome’s day‑to‑day affairs.
Sejanus enacted sweeping reforms that cemented the Guard’s power: he relocated their barracks from the outskirts into the heart of the city, constructing the massive Castra Praetoria that would serve as their headquarters for three centuries. These moves not only increased the Guard’s visibility but also entrenched their political clout.
His ultimate ambition was the imperial throne itself. To clear his path, Sejanus orchestrated the murder of Tiberius’s heir, Drusus Julius Caesar, allegedly by seducing Drusus’s wife, Livia, and poisoning the young prince. He also systematically eliminated other potential rivals, purging noble families that might challenge his authority.
Sejanus’s downfall came abruptly in 31 CE. Tiberius, perhaps finally realizing the threat, dispatched a sealed letter to Rome accusing Sejanus of treason. The Praetorians turned on their former leader, and he was swiftly executed, ending his brief but dramatic bid for power.
4 Assassination Of Elagabalus
After Macrinus’s brief reign, the Severan dynasty resurfaced when Julia Maesa, Caracalla’s aunt, engineered a revolt that placed her 14‑year‑old grandson, Elagabalus, on the throne. Though youthful, Elagabalus’s four‑year rule was marked by scandalous religious rites, extravagant banquets, and a lifestyle that shocked traditional Roman sensibilities.
The emperor’s excesses alienated every major constituency: the Senate, the populace, and crucially, the Praetorian Guard. Even his own grandmother, Julia Maesa, turned against him, plotting his removal. By 222 CE, the Guard had grown weary of his decadence and decided to replace him with his cousin, Severus Alexander.
When Elagabalus entered the Praetorian camp, the soldiers turned on him, slaying him in a brutal public execution. His head was severed, his naked corpse dragged through the streets, and his mother, lover Hierocles, and other close associates were also put to death. The Guard’s decisive action ended a turbulent chapter and ushered in a more conventional reign.
3 Praetorian Guard Chooses The Wrong Side
By the early fourth century, the Praetorian Guard had become a seasoned political force, but its loyalties were not always wisely placed. During the civil war that pitted Maxentius, Licinius, and Constantine against one another, the Guard threw its weight behind Maxentius, who had previously bolstered its numbers after Diocletian had tried to curb its influence.
Maxentius’s gamble backfired spectacularly at the Battle of the Milvian Bridge in 312 CE. Constantine’s forces decisively defeated Maxentius, who drowned in the Tiber River during the rout. Constantine then turned his attention to Licinius, ultimately defeating him as well and consolidating power as sole emperor by 324 CE.
Recognizing the Guard’s unreliability, Constantine dissolved the Praetorian Guard in 313 CE, dismantling their barracks in a public spectacle and redistributing the surviving soldiers to distant provinces. This act marked the end of a three‑century institution that had once been the empire’s most feared elite.
2 Conspiracy Against Caligula
The year 41 CE was a whirlwind of intrigue for the Praetorian Guard. First, they assassinated Emperor Caligula, then they thwarted a plan to restore the Roman Republic, and finally they crowned Claudius as the new emperor.
Caligula’s increasingly erratic and despotic rule made him a target for several conspiracies. The decisive plot was led by Praetorian tribune Cassius Chaerea and the centurion Cornelius Sabinus. According to Suetonius, Chaerea approached the emperor in a deserted corridor and, with his men, stabbed Caligula thirty times. The Guard then moved swiftly to eliminate Caligula’s wife and infant daughter.
Chaerea had hoped his actions would pave the way for a republican revival, but the majority of the Praetorians preferred the stability of imperial rule. When the conspirators realized the Guard would not support a republic, they rescued Claudius—the last surviving member of the Julian line—protecting him from harm. With the Guard’s backing, Claudius was proclaimed emperor, while Chaerea and his fellow plotters were executed for treason.
1 Auction Of The Imperial Title
The most egregious abuse of power by the Praetorian Guard unfolded in 193 CE, when they literally auctioned off the empire to the highest bidder. The debacle began when the Guard turned on Emperor Pertinax, who had attempted to curb their excesses and restore discipline.
In the wake of Pertinax’s murder, his former father‑in‑law, Sulpicianus, offered the Guard a generous sum to secure their support. Seizing the opportunity, the Guard opened a public bidding war, inviting any wealthy Roman to compete for the throne.
A senator named Didius Julianus outbid his rivals, paying a staggering amount to become emperor. Unsurprisingly, his purchase sparked outrage across the empire, igniting the Year of the Five Emperors. Julianus’s reign lasted less than three months before he was executed, illustrating the peril of allowing a mercenary guard to dictate imperial succession.