During the crisis of the 3rd century, there was a year (238 CE) in which there were six different emperors:
- Maximinius Thrax: a legionary general who was elected by the Praetorian Guard after Emperor Severus Alexander was assassinated by his own army. Thrax was very unpopular in the Senate (in part because he was executing a lot of Senators for plotting against him), and then faced a revolt in North Africa which led the Senate to name someone else as Emperor. In the process of crushing these revolts, Thrax led a very poorly-organized siege of Aquileia, and when he ran out of food and sickness spread because of tainted water, his men assassinated him, his son, and his lieutenants and sent their heads on pikes to Rome.
- Gordian I and Gordian II. When the North African revolt started, the revolutionaries proclaimed the governor Gordian to be their emperor. Because he was 80 at the time, he made his son (also called Gordian) co-emperor. The Senate in Rome recognized both father and son, but unfortunately the governor of Numidia hated the Gordians, invaded the province of North Africa, and defeated the Gordians at Carthage. Gordian II was killed in the fighting and Gordian I hanged himself when he heard of his son’s death. It wasn’t all bad for them, they ended up declared gods by the Senate after their deaths.
- Pupienus and Balbinus. After the death of the Gordians, the Senate needed a new emperor to lead them, because Maximinus was barreling down on Rome with his army (before he got stopped at Aquileia and it all went bad). So they elected two senior senators to be co-emperors. This was not popular with the people of Rome, who rioted. While Pupienus was sent out with an army to fight Maximinus, who died without Pupienus doing anything, Balbinus was supposed to keep order in Rome and failed miserably. Riots led to fires, the two emperors couldn’t get along and literally divded the imperial palace between them like in the Odd Couple, and the two became incredibly paranoid about the other, so wouldn’t let the army come into the city to restore order lest it be used by one against the other. Finally, the Praetorian Guard, who hadn’t liked the Senatorial revolt against Thrax, seized the two of them mid-argument, tortured them, and then hacked them to death in the Praetorian bath house (presumably because it had drains to deal with the blood).
- Gordian III. Remember how I said the people of Rome didn’t like Pupienus and Balbinus? Well, for some reason, they prefered the thirteen-year-old Gordian III, the grandson of Gordian I. To placate the people of Rome, Pupienus and Balbinus named Gordian to the rank of Caesar, making him the heir-apparent to their wise old caretakers. After the assassination of those two, Gordian III became sole emperor, but with the Senate running the government and buying off the Praetorians by marrying Gordian to the daughter of the head of the Praetorian Guard. He made it to 244 before dying in disputed circumstances, and also was declared a god by the Senate, picking up the hat trick for the Gordian family.
And thus passed the Year of the Six Emperors. If you’d like to know more, I highly recommend Mike Duncan’s HIstory of Rome podcast.