In AD 193, a purple robe became the deadliest possession in the Roman world. Pressed against the cloth, a faint warmth still lingered—the last heat of the body that had worn it only hours before. That body belonged to Commodus, strangled in his own bath by a wrestler on the palace payroll. Now the robe had passed to Publius Helvius Pertinax, a 66-year-old soldier with a stooped back and a career earned in the provinces where men froze or bled for their pay.
Pertinax was the son of a freedman who had once taught grammar before trading the wax tablet for the sword. He had served as tribune in Syria, commander on the Danube, governor of Britain, proconsul of Africa, and prefect of the city. He had survived a mutiny in Britain that cut down men around him in his own headquarters. Now he inherited the throne of a man who had spent a decade renaming the world.
Commodus had renamed the months after himself, styled the legions the Commodian legions, and demanded statues of himself as Hercules. He had clubbed crippled men in the arena and shot tethered ostriches with crescent-headed arrows, building the treasury a million sesterces for each appearance. His final plan for the new year was to murder both incoming consuls and step from the gladiators’ barracks in a fighter’s tunic. He never reached that morning.
His mistress Marsha found her own name on his execution list, and after poison failed, a wrestler named Narcissus held him under the bath water until he stopped struggling. Rome exhaled. The Senate hailed Pertinax as the man who would restore a Commonwealth they thought buried. He wasted no hours.
On his first morning, he refused the title Augusta for his wife and Caesar for his son. He walked the streets on foot and greeted men by name. Dio reports the people wept to see an emperor who behaved like a citizen. Then he went to the treasury and found it empty.
Commodus had drained it to the copper. To refill it, Pertinax ordered the palace stripped of every luxury and had it hauled to the forum for a public sale. Wagons rolled out with embroidered silks, gold and silver plate, gem-crusted weapons that had never touched a battlefield. The exotic beasts stockpiled for slaughter were led out in chains and sold.
The palace singers, charioteers, and even the children Commodus had gathered across the provinces were sold on. The crowd picked the bones of a reign in the shadow of the Temple of Saturn. But there was a fifth group watching the treasure move, and they were doing arithmetic of their own. They saw an emperor who did not grasp how power was actually financed in this new Rome.
They were the Praetorian Guard, nine cohorts strong, quartered in their own fortress inside the city walls, the Castra Praetoria. They drew triple the pay of legionaries and served fewer years for it. They had made and unmade rulers before—cutting down Caligula, hauling Claudius out from behind a curtain to make him emperor. Under Commodus, their power had swelled past restraint.
They sold offices, ran protection over markets, and decided who reached the emperor and who did not. The men who drowned Commodus had promised the guard a fortune in the new emperor’s name. Pertinax, built of principle, was appalled by the figure. He agreed to 12,000 sesterces a man, then could not even pay that at once.
He handed a standing army a promise of money he did not have. Then he set out to restore discipline: he told them to stop shaking down citizens, shut their side rackets, and marched them back onto the drill field to sweat like soldiers again. Every reform he called virtue. They read it as theft from their own purse.
A plot surfaced to raise a consul named Falco to the throne. Pertinax pardoned him and refused to let a single senator die. That mercy looked to the barracks like weakness. Worse, when the plot broke, some Praetorians were dragged in for questioning, and one died under it.
To the guard, that was blood owed. His reign lasted 87 days. On the 28th of March, AD 193, a faction of the guard decided they had waited long enough. It was no elaborate plot—just two or three hundred angry men sour about their pay and their lost rackets, arming in the barracks and pouring out through the fortress gate in the middle of the day.
They marched toward the Palatine with drawn swords. Crowds scattered, merchants pulled down their shutters, and the palace emptied. Even Laetus, the prefect who had helped kill Commodus and set Pertinax in his place, walked away from the man he had raised. Pertinax refused to run.
He sent his father-in-law Sulpicianus off to the barracks to calm the men, then walked out to meet the mob in the courtyard of the palace. The sight of the gray emperor standing unarmed stopped them for a moment. He began to speak, steady, measured, reproaching them for breaking faith. Dio says the greater part wavered and looked at the ground.
Then a single auxiliary, a Tungrian from the Rhine named Tausius, raised his spear, shouted that this was the sword the soldier sent, and threw. The point struck the emperor. The spell broke. The rest surged in.
Pertinax pulled his toga over his head, the old gesture of a Roman meeting his end, and spoke a last word to Jupiter the Avenger. They cut him down where he stood. Only a chamberlain named Eclectus drew his blade, cut down two attackers, and died over the body of the emperor he was sworn to guard. The killers struck off the emperor’s head.
The Praetorians carried their trophy into the streets, fixed the head on a spear, and lifted it above the crowds. To the Senate it said: your chosen man is finished. And beneath that ran an advertisement, plain as a notice nailed to a post: the office of emperor stands empty again. The guard withdrew behind the walls of the Castra Praetoria and barred the gates.
Out of the silence came the act no one was prepared to hear. From the top of the ramparts, a herald announced that the Roman Empire was now for sale. Whoever paid the most to the men behind these walls would be handed the purple. At the foot of the wall, one man already stood hammering on the gate with a purse in his hand.
It was Sulpicianus, the dead emperor’s own father-in-law, come to buy the throne over his son-in-law’s severed head. A second bidder arrived: Marcus Didius Salvius Julianus, one of the richest men in Rome, a senator of consular rank who had been raised in the household of Marcus Aurelius’s mother. The bidding war was shouted through the iron of the military gate. Julianus, desperate, threw out 25,000 sesterces a man, and sweetened it with a promise to restore the memory of Commodus, whom the guard had loved.
That may have decided them. The gates swung inward for their new master. The bill came to 300 million sesterces. A frontline legionary earned about 1,200 a year.
Julianus had promised every Praetorian more than twenty times that, money enough to keep an entire legion in the field for nearly twenty years. And he did not have the cash. The treasury Pertinax had scraped together was thin, and Julianus would spend his reign owing the very men who had chosen him. The guard marched him out in a hollow square of drawn swords, so tight that Dio says he moved as if under guard against his own people.
The Senate, with steel at their backs, voted him the titles of Augustus and Emperor. But the instant he stepped beyond the reach of Praetorian blades, he learned he had bought the office and none of the consent that gives it life. The city refused him. A mob spat curses, called him thief and parricide, flung stones, and shut their shops in mourning.
At the Circus Maximus, a crowd of over a hundred thousand chanted the name of Pertinax, and then another name: Pescennius Niger, the governor of Syria. They were calling to the legions on the far frontiers, begging for a civil war. On the frontiers, the legions heard. In Antioch, the eastern legions wrapped a purple of their own weaving around their commander Pescennius Niger.
In Britain, the garrison did the same for their governor, Decimus Clodius Albinus. And on the Danube in Pannonia, the most feared army in the empire raised the purple over their general, Lucius Septimius Severus, at Carnuntum on the 9th of April. In a matter of weeks there were four emperors. The auction had not delivered an empire.
It had cracked it into four. Of the three challengers, Severus was the deadliest. The Danube legions lay only a ten-day march from the Alpine passes into Italy. He commanded sixteen legions, the roughest troops in the service, men who had spent careers killing across the frozen frontier.
He did not present himself as a usurper marching for a crown. He called himself the avenger of Pertinax, styled himself Septimius Severus Pertinax, and let his soldiers believe the gods had marked him for this. Before moving south, he made a cold and clever stroke. He sent a message to Clodius Albinus in Britain offering him the junior rank of Caesar, his heir and colleague.
Albinus, flattered, took it and let his legions stand down. Severus had no thought of sharing anything. He was renting Albinus’s loyalty for a season, buying his stillness cheaply. With the western flank quiet, Severus gathered his legions and crossed into Italy.
Town after town along the Flaminian Way opened its gates. For Didius Julianus, the robe he had purchased became the warrant for his own death. His reign lasted 66 days. He could not pay the guard the full sum, so his own bodyguards despised him.
He tried to buy the mob’s love with games; the mob threw it back. He sent centurions to murder Severus on the march; they were seized or went over. He brought war elephants into the drill; the beasts threw their riders. The Senate condemned him and named Severus the one lawful emperor.
Dio records his last words as a question with no answer in it: What evil have I done? Whom have I killed? A single soldier drew his blade. The purple was stripped from the body of the man who had bought the world.
Severus came into Rome in the first days of June AD 193 wearing a plain toga, walking on foot through the gates while his legions pitched tents outside the sacred boundary. His first task was to take apart the machine that had made and sold three emperors in six months. He summoned the whole Praetorian Guard to assemble outside the city, unarmed, in parade dress, to swear the oath to their new emperor. They came as told, leaving their swords behind the brick walls.
As they formed their ranks on the grass, the Pannonian veterans in full battle order closed around them in a ring of iron with no gap in it. Severus rode in among them and named their crimes: the murder of Pertinax, the abandonment of their oath, the auction of the throne through the bars of their own gate. He stripped them of rank and discharged them in disgrace, forbade them to come within a hundred miles of the city on pain of death, and had the men who actually struck down Pertinax taken away for execution. The most feared unit in the Roman world was dissolved in an afternoon, and not one throat was opened to do it.
Then Severus built a new guard of ten thousand men, filled not with privileged Italians but with hard men drawn from his own frontier legions. He raised the pay of the ordinary legionary for the first time in more than a century, let soldiers marry, opened the higher ranks to men risen from the barracks, and stationed a full legion on the Alban Hills a few miles from Rome—the first time a legion had ever been quartered in Italy. The guard no longer belonged to Rome. It belonged to the emperor.
With the capital in his fist, Severus turned east to Pescennius Niger in Syria. This one was a war. Niger held the rich eastern provinces, including Egypt and Byzantium, and commanded nine legions. The campaign ground across Asia Minor for more than a year.
Roman killed Roman at Cyzicus and Nicaea, tens of thousands of trained legionaries feeding a fire lit by one man’s claim. The last clash came in the spring of AD 194 on the plain of Issus, the same ground where Alexander had shattered Darius five centuries before. A sudden storm drove wind and rain into Niger’s troops as they charged, and they took it for a judgment of the gods. Dio puts the dead at 20,000 on Niger’s side alone.
Niger fled toward the Parthian frontier, was run down near Antioch, and killed on the spot. His head was sent to the walls of Byzantium, where his last loyalists still held out. They did not surrender at the sight. The city held its gates for two more years until hunger drove the defenders to eat the dead.
When it finally fell, Severus tore down its walls and stripped it of its rights. One copy of the robe was gone, and its price had been a city. In the west, Clodius Albinus still held the rank of Caesar for three years, trusting the promise that had bought his silence. Severus tested the loyalty of Albinus’s commanders and then, in AD 195, let the mask drop entirely.
He had the Senate formally deify Commodus, the tyrant he had once marched to avenge, declared himself the adopted son of Marcus Aurelius, and named his own elder son Caracalla as his heir and Caesar. Albinus was struck out of the succession with a stylus. There was no path left but the sword. Albinus took the title Augustus, gathered his three British legions and the forces of Spain and Gaul, and set his headquarters at Lugdunum.
On the 19th of February AD 197, the two largest armies ever thrown against each other in a Roman civil war met on a broad plain outside the city. Dio sets each side at 150,000 men. The battle ran two days. At one turn, Severus’s own wing buckled and broke, and he was thrown from his horse.
He tore off his purple cloak so no enemy would mark him, then seized a standard, drew his sword, and hauled himself back toward the fighting, screaming at his men to turn and stand. His refusal to run held the line. On the far wing, his cavalry commander finally wheeled and crashed into the flank of Albinus’s legions. The rebel army folded.
Albinus fled back inside the walls of Lugdunum and took his own life by the river. Severus made no gesture of mercy over the body. He had Albinus’s stripped corpse laid on the earth before his command tent, rode his horse back and forth across it, then sent the head to Rome to stand on a spike in the forum. He sacked Lugdunum, the richest city of Gaul, and read out to the Senate the letters seized from Albinus’s baggage, having twenty-nine senators put to death.
He told them to their faces that he admired the cruelty of Sulla and Marius more than the mildness of the emperors they had loved. The journey of the purple robe was finished. It had begun on the shoulders of Commodus, held under the water of his bath. It had passed to Pertinax, killed for trying to give it back its dignity.
It had been sold to Didius Julianus, killed because coin could not defend it. Its authority had been copied by Niger and Albinus, and both were destroyed for the presumption of wearing it. Now it came back to Rome on the back of Septimius Severus, and it was not the same object it had been. It no longer stood for the Senate’s blessing, nor even for the guard’s patronage.
It had become the uniform of the strongest warlord, the personal property of whoever held the most and the best legions. Power no longer rose from the Senate House. It flowed out of the marching camps on the rivers. Severus ruled fourteen more years, campaigning against the Parthians, sacking their capital at Ctesiphon in 198, and crossing to Britain to drive north against the Caledonians.
He died at Eboracum in northern Britain in AD 211, worn out and ill. Dio preserves the council he gave his sons from his deathbed: Be at peace with each other, enrich the soldiers, and take no account of anyone else. His sons ignored the first part almost at once. Within a year, Caracalla had his brother Geta killed in their mother’s arms and struck his name from every inscription in the empire.
But they kept the second. That was the thread now woven through the purple. What remained was a military dictatorship that no longer troubled to disguise itself. The precedent set in AD 193, the year the throne went to the highest bidder, would shadow Rome for the next hundred years, loosing civil war after civil war as one general after another followed the road Severus had cut.
In the fifty years that came to be called the Crisis of the Third Century, more than two dozen men would claim the purple and die for it, most of them killed by their own soldiers. The gate that swung open in AD 193 never truly closed again.