Italy, Praetorian prefecture of

Nepotianus is the son of Eutropia, half-sister of Emperor Constantine I, and of Virius Nepotianus; on his mother's part, he is grandson of Emperor Constantius Chlorus and Flavia Maximiana Theodora.

He proclaims himself emperor and enters Rome with a band of gladiators on June 3, 350, which causes the Praefectus urbi Titianus (or Anicius, or Anicetus), allied to Magnentius, to flee, after being defeated at the head of an undisciplined force of Roman citizens.

Magnentius quickly deals with the situation by sending his trusted magister officiorum Marcellinus to Rome.

Nepotianus is killed in the resulting struggle (June 30, 350), his head put on a lance and brought around the city (Eutropius).

In the following days, Eutropia too is killed, within the persecution of the supporters of Nepotianus, most of whom are senators.

Magnentius fails, however, to win failing to win recognition from Constantius.

The domed, circular Mausoleum of Santa Costanza, constructed in Rome around 350 to house the remains of one of Constantine’s daughters, is an early example of the centralized sanctuary type of ecclesiastical architecture.

An alternative to the longitudinal basilica, the more diverse centralized type, which could be built to a circular, polygonal, square, or Greek-cross plan, could serve as a baptistery, a memorial, a martyrium, a mausoleum, or as a congregational church.

Extensive mosaics decorate the ambulatory vaults of the Mausoleum of Santa Costanza with geometric and figurative patterns.

Among these are a magnificent version of the popular Hellenistic motif called the "unswept floor"—a scattering of shells, bowls, pitchers, branches, and birds that might have covered a floor after a feast.

The mausoleum’s dome is adorned with Old and New Testament scenes (now lost).

Magnentius is able to successfully ambush the emperor's forces near Adrana (Atrans) in the spring, and advance into the province of Pannonia Inferior.

The usurper Magnentius, refusing Constantius' offer of compromise and suffering setbacks at Siscia (modern Sisak, Croatia) and Sirmium (modern Sremska Mitrovica, Serbia), pursues Constantius to …

The outstanding marble sarcophagus of Christian politician Junius Bassus, vir clarissimus and vicarius of Rome as well as praefectus urbi from March 25 to 25 August 25, 359, is, with its double frieze of figures grouped in small architectural niches, an early example of the high relief sculpture favored by early Christians.

The youthful, beardless Christ in the upper central niche draws from images of the pagan deity Apollo, an example of the adaptation of figures from pagan mythology as Christian images and symbols.

Gallus, in an exhibition of his presumed soon-to-be Augustus powers, stages a chariot race in Constantinople's Hippodrome and crowns the victor, an honor reserved only for those that are Augusti.

This insolence of Gallus enrages Constantius, further adding to his dislike for the upstart Caesar.

In an attempt to further isolate Gallus from any form of military protection, Constantius has the garrisons removed from the towns in Gallus's path to Mediolanum.

Gallus arrives to Poetovio in Pannonia, and Barbatio, an officer who had been supporting Gallus' dismissal within Constantius' court, surrounds the palace of the caesar and arrests him, stripping Gallus of the imperial robes, but assuring him that no harm will come to him.

Gallus is led to Pola in Istria (now Pula, Croatia), where he is interrogated by some of the highest officials of Constantius' court, including the eunuch praepositus cubiculi Eusebius and the agens in rebus Apodemius.

Gallus tries to put the blame of all of his actions on Constantina, but Constantius sentences him to death; the emperor later changes his mind, and orders the caesar to be spared, but Eusebius orders that the news is not to reach the executioners.

An official register of 354 lists nine hundred and fifty-two baths in the city of Rome.

Constantius, after dealing with the rebellions of Magnentius and Sylvanus, feels the need for a permanent representative in Gaul.

His twenty-three year-old nephew Julian is in 355 summoned from Greece to appear before the emperor in Mediolanum.

This is a difficult decision for a paranoid ruler who regards all his relatives with intense suspicion and has already put to death two uncles and seven cousins, including Julian's half-brother Constantius Gallus, but Constantius' own family purges had left him little choice: Julian is his sole surviving adult male close relative.

Julian, who has studied at Pergamon, at Ephesus, and lately at Athens, has adopted the cult of Sol Invictus, the Unconquered Sun.

He had arrived at Sirmium “still wearing his student's gown.”

Julian is on November 6 duly proclaimed and invested as Caesar of the West, an honor that he accepts with justifiable foreboding, and marries Constantius' sister, Helena. (She will die after five years of marriage-the fate of their issue, if any, is unknown.)

After his experience with Gallus, Constantius intends his representative to be more a figurehead than an active participant in events, so he at once packs Julian off to Gaul with a small retinue; Constantius' prefects in Gaul will keep him in check.

Julian, at first reluctant to trade his scholarly life for war and politics, will eventually take every opportunity to involve himself in the affairs of Gaul.