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date: 18 January 2019

Constantius I, Flavius Valerius, Roman emperor

Flavius Valerius Constantius I, (perhaps Flavius Iulius before 293; nicknamed, not before the 6th cent., Chlorus), born no later than 250 ce, of Illyrian stock; stories of his relationship with Claudius II are fictions of Constantine's propagandists. Constantius served as an army officer, as governor of Dalmatia, and possibly as praetorian prefect of Maximianus Augustus (Maximian), whose daughter or stepdaughter Theodora he married, having put away Helena, the mother of Constantine I. On the establishment of the tetrarchyDiocletian appointed him Caesar, Maximian invested him at Milan (Mediolanum, 1 March 293), and he took charge of Gaul, basing himself mainly at Trier (Augusta Treverorum). His first task was to recover NE Gaul, held, with Britain, by the usurper Carausius. In summer 293 he stormed Boulogne; but Allectus, who murdered Carausius, retained Britain. Many of Carausius’ defeated barbarian allies, Chamavi and Frisii, were settled within the empire. In 296, with Maximian guarding the Rhine, Constantius and his praetorian prefect, Asclepiodotus, took ship for Britain. Asclepiodotus, landing near Clausentum (Bitterne), routed and killed Allectus; Constantius, separated from his prefect, came up the Thames to London in time to destroy the survivors of the beaten army. Constantius showed mercy to Britain and restored its defences. His other campaigns included a spectacular victory over the Alamanni at Langres (302). He failed fully to implement in his territories Diocletian's edicts against Christians (304), merely demolishing some churches. (See christianity.) On the abdication of Diocletian and Maximian (1 May 305) Constantius had Spain added to his territories but his rank as senior Augustus was curbed by the fact that both Caesars, Flavius Valerius Severus and C. Galerius Valerius Maximinus, were creatures of Galerius Augustus, who also held Constantine as a virtual hostage. Constantius crossed to Britain and asked that his son be released. Constantine was able to reach him fast enough to assist in his last victory, over the Picts, and to be proclaimed emperor by the army at York (Eburacum) when Constantius died there (25 July 306). His premature death, and Constantine's proclamation, wrecked Diocletian's tetrarchic system. Constantinian propaganda bedevils assessment of Constantius, yet he appears to have been an able general and a generous ruler. By Theodora he had six children, half-siblings of Constantine; grandsons included Gallus Caesar, Julian, and the usurper (350) Nepotian.


Realencyclopädie der Classischen Altertumswissenschaft, s.v. “Constantius 1.”Find this resource:

B. Leadbetter, Galerius and the Will of Diocletian (2009).Find this resource:

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