The Year of the Six Emperors was the year 238 AD, during which six people were recognised as emperors of Rome.
The emperor at the beginning of the year was Maximinus Thrax, who had ruled since 235. Later sources claim he was a cruel tyrant, and in January of 238, a revolt erupted in North Africa. The Historia Augusta states:
"The Romans could bear his barbarities no longer — the way in which he called up informers and incited accusers, invented false offences, killed innocent men, condemned all whoever came to trial, reduced the richest men to utter poverty and never sought money anywhere save in some other's ruin, put many generals and many men of consular rank to death for no offence, carried others about in waggons without food and drink, and kept others in confinement, in short neglected nothing which he thought might prove effectual for cruelty — and, unable to suffer these things longer, they rose against him in revolt."
Some young aristocrats in Africa murdered the imperial tax-collector and then approached the regional governor, Gordian, and insisted that he proclaim himself emperor. Gordian agreed reluctantly, but as he was 80 years old, he decided to make his son joint emperor, with equal power. The senate recognized father and son as emperors Gordian I and Gordian II, respectively.
Their reign lasted for only 20 days. Capelianus, the governor of the neighboring province of Numidia, held a grudge against the Gordians. He led an army to fight them and defeated them decisively at Carthage. Gordian II was killed in the battle, and on hearing this news, Gordian I hanged himself.
Meanwhile, Maximinus, now declared a public enemy, had already begun to march on Rome with another army. The senate's previous candidates, the Gordians, had failed to defeat him, and knowing that they stood to die if he succeeded, the senate needed a new emperor to defeat him. With no other candidates in view, on 22 April 238 they elected two elderly senators Pupienus and Balbinus (who had both been part of a special senatorial commission to deal with Maximinus) as joint emperors.