Iulius Nepotianus (died June 30, 350), commonly known in English as Nepotian, was a member of the Constantinian dynasty who reigned as a short-lived usurper of the Roman Empire. He ruled the city of Rome for twenty-eight days, before being killed by his rival usurper Magnentius' general Marcellinus.
Nepotianus was the son of Eutropia, half-sister of Emperor Constantine I, and of Virius Nepotianus. On his mother's side, he was the grandson of Emperor Constantius Chlorus and Flavia Maximiana Theodora.
After the revolt of Magnentius, Nepotianus proclaimed himself "emperor" and entered Rome with a band of gladiators on 3 June 350. After attempting to resist Nepotianus with an undisciplined force of Roman citizens, the defeated Praefectus urbi Titianus (or Anicius, or Anicetus), a supporter of Magnentius, fled the city.
Magnentius quickly dealt with this revolt by sending his trusted magister officiorum Marcellinus to Rome. According to Eutropius, Nepotianus was killed in the resulting struggle (on 30 June), his head put on a lance and borne around the city. In the following days, his mother Eutropia was also killed, during the persecution of the supporters of Nepotianus, most of whom were senators.
Nepotianus (died 465) was a general of the Western Roman Empire.
Nepotianus married the sister of Marcellinus, the semi-independent ruler of Dalmatia; the couple had a son, Julius Nepos, last Western Roman Emperor.
In 458 he was comes et magister utriusque militiae and together with Aegidius, he commanded the army of the Western Emperor, Majorian. That same year Majorian started a military campaign to re-conquer Gaul; the army, reinforced by some barbarian mercenaries, dislodged the Visigoths of Theodoric II from Arelate and obliged them to return to their condition of foederati. With the help of his new foederati, Majorian entered in the Rhone Valley, conquering its populations "some by arms and some by diplomacy". He defeated the Burgundians and besieged and conquered the city of Lugdunum: the rebel city was heavily fined, while the Bagaudae were forced to join the Empire.
In 459, some envoys of Nepotianus and of the gothic comes Sunieric arrived in Gallaecia to announce the victory of Majorian and the treaty between the Romans and the Visigoths.
Nepotianus may refer to: