Honorius (emperor) in the context of "West Roman Empire"

In modern historiography, the Western Roman Empire were the Roman Empire's western provinces, collectively, during any period in which they were administered separately from the eastern provinces by a separate, independent imperial court. Particularly during the period from AD 395 to 476, there were separate, coequal courts dividing the governance of the empire into the Western provinces and the Eastern provinces with a distinct imperial succession in the separate courts. The terms Western Roman Empire and Eastern Roman Empire were coined in modern times to describe political entities that were de facto independent; contemporary Romans did not consider the Empire to have been split into two empires but viewed it as a single polity governed by two imperial courts for administrative expediency. The Western Empire collapsed in 476, and the Western imperial court in Ravenna disappeared by 554, at the end of Justinian's Gothic War.

Though there were periods with more than one emperor ruling jointly before, the view that it was impossible for a single emperor to govern the entire Empire was institutionalized by emperor Diocletian following the disastrous civil wars and disintegrations of the Crisis of the Third Century. He introduced the system of the Tetrarchy in 286, with two senior emperors titled Augustus, one in the East and one in the West, each with an appointed subordinate and heir titled Caesar. Though the tetrarchic system would collapse in a matter of years, the East–West administrative division would endure in one form or another over the coming centuries. As such, the unofficial Western Roman Empire would exist intermittently in several periods between the 3rd and 5th centuries. Some emperors, such as Constantine I and Theodosius I, governed, if briefly, as the sole Augustus across the Roman Empire. On the death of Theodosius in 395, the empire was divided between his two infant sons, with Honorius as his successor in the West governing briefly from Mediolanum then from Ravenna, and Arcadius as his successor in the East governing from Constantinople.

Ravenna (/rəˈvɛnə/ rə-VEN-ə; Italian: [raˈvenna], also locally [raˈvɛn(n)a] ; Romagnol: Ravèna, Ravêna) is the capital city of the Province of Ravenna, in the Emilia-Romagna region of Northern Italy. It was the capital city of the Western Roman Empire during the 5th century until its collapse in 476, after which it served as the capital of the Ostrogothic Kingdom and then the Byzantine Exarchate of Ravenna. It has 156,444 inhabitants as of 2025.

Initially settled by the Umbri people, Ravenna came under Roman Republic control in 89 BC. Octavian built the military harbor of Classis at Ravenna, and the city remained an important seaport on the Adriatic until the early Middle Ages. The city prospered under imperial rule. In 401, Western Roman emperor Honorius moved his court from Mediolanum to Ravenna; it then served as capital of the empire for most of the 5th century.

Aelia Flavia Flaccilla (died 386), better known simply as Aelia Flacilla or Flacilla, was a Roman empress and first wife of the Roman Emperor Theodosius I. She was of Hispanian Roman descent. During her marriage to Theodosius, she gave birth to two sons – future Emperors Arcadius and Honorius – and a daughter, Aelia Pulcheria.

Stilicho (/ˈstɪlɪkoʊ/; c. 359 – 22 August 408) was a military commander in the Roman army who, for a time, became the most powerful man in the Western Roman Empire. He was partly of Vandal origins and married to Serena, the niece of emperor Theodosius I. He became guardian for the underage Honorius. After years of struggle against barbarian and Roman enemies, political and military disasters finally allowed his enemies in the court of Honorius to remove him from power. His fall culminated in his arrest and execution in 408.

The Valentinian dynasty, commonly known as the Valentinianic dynasty, was a ruling house of five generations of dynasts, including five Roman emperors during late antiquity, lasting nearly a hundred years from the mid fourth to the mid fifth century. They succeeded the Constantinian dynasty (r. 306–363) and reigned over the Roman Empire from 364 to 392 and from 425 to 455, with an interregnum (392–425), during which the Theodosian dynasty ruled and eventually succeeded them. The Theodosians, who intermarried into the Valentinian house, ruled concurrently in the east after 379.

The Valentinian dynasty's patriarch was Gratianus Funarius, whose sons Valentinian I and Valens were both made Roman emperors in 364. Valentinian I's two sons, Gratian and Valentinian II both became emperors. Valentinian I's daughter Galla married Theodosius the Great, the emperor of the eastern empire, who with his descendants formed the Theodosian dynasty (r. 379–457). In turn, their daughter, Galla Placidia married a later emperor, Constantius III (r. 421–421). Their son, Valentinian III (r. 425–455), who ruled in the west, was the last emperor of the dynasty, whose death marked the end of dynasties in the western empire. During the interregnum, Theodosius' son Honorius ruled in the west, and concurrently with Constantius III in 421. The dynasty has been labelled as Pannonian, based on the family origin in Pannonia Secunda in the western Balkans.

The anti-paganism policies of the early Byzantine Empire ranged from 395 till 567. Anti-paganism laws were enacted by the Byzantine Emperors Arcadius, Honorius, Theodosius II, Marcian and Leo I the Thracian. They reiterated previous legal bans, especially on pagan religious rites and sacrifices and increased the penalties for their practice. The pagan religions had still many followers but they were increasingly obliged to keep under cover to formally comply with the edicts. Significant support for paganism was present among Roman nobles, senators, magistrates, imperial palace officers, and other officials.

Many Christians pretended to be such while continuing pagan practices, and many converted back to paganism; numerous laws against apostasy kept being promulgated and penalties increased since the time of Gratian and Theodosius. Pagans were openly voicing their resentment in historical works, like the writings of Eunapius and Olympiodorus, and books blaming the Christian hegemony for the 410 Sack of Rome. Christians destroyed almost all such pagan political literature, and threatened copyists with cutting off their hands.

Constantius III (died 2 September 421) was briefly Western Roman emperor in 421, having earned the throne through his capability as a general under Honorius. By 411 he had achieved the rank of magister militum, and in the same year he suppressed the revolt of the usurper Constantine III. Constantius went on to lead campaigns against various barbarian groups in Hispania and Gaul, recovering much of both for the Western Roman Empire. He married Honorius' sister Galla Placidia in 417, a sign of his ascendant status, and was proclaimed co-emperor by Honorius on 8 February 421. Constantius reigned for seven months before dying on 2 September 421.