Short answers, pulled from the story.
Balbinus, whose full name was Decimus Caelius Calvinus Balbinus, was Roman emperor alongside Pupienus for three months in 238 AD, the Year of the Six Emperors. The Senate elected both men as co-emperors in April 238 following the defeat of the Gordians.
Balbinus was assassinated by members of the Praetorian Guard. Pupienus had warned him of the plot, but Balbinus believed the Guard intended to secure the throne for him personally. Both co-emperors were killed.
Balbinus served twice as consul; his first consulship is believed to have been around 203 or in July 211, and his second came in 213 as the colleague of Caracalla. He was also one of the Salii priests of Mars.
The sarcophagus of Balbinus is held at the Museo di Pretastato, located at the catacombs of Praetextatus in the Park of the Caffarella near the Appian Way in Rome. It is the only surviving Roman Imperial sarcophagus of its type.
Balbinus was a senior senator with patrician birth, twice a consul, and well-connected across Rome's political elite. Edward Gibbon described him as an admired orator, a poet of distinguished fame, and a wise magistrate with experience across the empire's interior provinces.
Although Balbinus was consistently described in historical sources as the civilian counterpart to the military Pupienus, his figure on the sarcophagus is carved in full military dress. The monument is also unique as the only surviving Roman Imperial sarcophagus of its type.