Didius Julianus won the Roman Empire in an auction held by the Praetorian Guard in 193 CE.
193 CE was a bad year for Roman emperors. The emperor Pertinax – the son of a slave – had come to power on the first day of the year. He was concerned (rightly so) about the Praetorian Guard.
Originally and ostensibly the emperor’s private bodyguards and intelligence network, the Praetorian Guard had grown into a significant political force that both deposed and appointed emperors according to their own interests. It was a member of the guard who assassinated Emperor Caligula in 41 CE, and the guard itself who appointed Claudius in his place afterwards. Claudius rewarded them with five years’ pay – and this set a rather worrying precedent.
Fast forward 152 years, and Rome was in a similar situation. Emperor Commodus had been assassinated, with the head of the Praetorian Guard as the leader of the conspiracy against him (Commodus, by the way, is the villain in the film Gladiator, although he did not die in the arena… he was poisoned by his mistress and then strangled in his bath – or maybe his bed – by his personal trainer).
Pertinax had been chosen by the guard to be the new emperor. They expected a substantial reward, but only received half of what was promised. Emperor Pertinax had a big ol’ target painted on his back from then on. He tried to reform the guard, reintroduce some military discipline, and actually managed to make some progress. For three months. Then the Praetorians rushed the palace and killed him.
Who would be the next emperor? That question, while important, was not at the forefront of the Praetorian Guard’s mind. The real question was this: how much money could they extract from the next emperor? It was time for an auction.
The bidders: Titus Flavius Claudius Sulpicianus, Pertinax’s father-in-law; Didius Julianus, the proconsul of North Africa. Sulpicianus was inside the Praetorian camp at the time and Julianus was not, so the advantage was his. He offered the enormous sum of 20,000 sesterces to each guard member. Guards at this time would have been paid about 2,500 sesterces a year, so you can imagine the size of this bid. But Julianus, immediately outside the encampment, shouted his bid: 25,000 sesterces each, ten years’ wages, if they would appoint him emperor instead. So they did.
Emperor Didius Julianus did not last long. The Roman legions revolted and marched on Rome. Julianus lacked any substantial power base, so he lost supporters with every advance by the more popular rebels. He was killed by a soldier exactly 66 days after the auction:
And so it came about that Julianus was slain as he was reclining in the palace itself; his only words were, “But what evil have I done? Whom have I killed?”