Constantinus Flavius Popilius Nepotianus was the grandson of Flavius Valerius Constantius (Chlorus) and Flavia Maximana Theodora. His parents were Virius Nepotianus and Eutropia, his mother being the half-sister of Constantine the Great. He and his two cousins, Julian II and Constantius Gallus, lived in semi-exile until Fausta was executed in 326. Nepotian served as consul in 336, but he must have kept a relatively low profile as not much is known about his life. Because of his very young age, he survived the purge in Summer 337 by the sons of Constantine the Great when they were eliminating many potential dynastic challengers.
On June 3, 350 AD, Nepotian was hailed emperor in Rome by a mob. Magnentius had taken control Rome around 20 weeks earlier, usurping the throne from the legitimate ruler, Constans. Nepotian and his loyalists murdered Anicius, the praetorian prefect of Italy under Magnentius. Over the next few days, they continued to purge Rome of those loyal to Magnentius. It is unclear if Nepotian was acting on his own, on behalf of the mob who installed him, or through his half-cousin Constantius II. Numismatically, it is possible he was acting as agent for Constantius II, since he issued coins both under his name and Constantius II.
Marcellinus led the counter-counter-rebellion – the same man who threw the party at which Magnentius was hailed emperor. Nepotian was killed during the confrontation on June 30, after ruling for only 27 days. He was beheaded and his head mounted on a lance and paraded through the city. Unsurprisingly, the purge of Nepotian’s followers immediately followed, seeing the murder of Eutropia and persecution of many senators.
Even though Nepotian only ruled a short time, he took full advantage of advertising it on coinage. All of his coins are rare, but he did issue solidi and AE2s. There are two reverse types – GLORIA ROMANORVM and VRBS ROMA, but three different obverse inscriptions. All six officinae in Rome were used and production appears to have been split evenly among them.
When Magnentius recaptured Rome, he elevated Decentius to Caesar and struck coins with two reverses celebrating the event – BIS RESTITVTA LIBERTAS (only for Magnentius and meaning that Rome was twice liberated) and RENOBATIO VRBIS ROME (issued for Magnentius and Decentius).