Constantius III

Roman emperor
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Quick Facts
Died:
September 2, 421, Ravenna, Italy
Title / Office:
emperor (421), Roman Empire
Notable Family Members:
spouse Aelia Galla Placidia

Constantius III (died September 2, 421, Ravenna, Italy) was a Roman emperor in 421.

Constantius came from Naissus (modern Niš, Serbia) in the province of Moesia. In 411, as magister militum (“master of the soldiers”) under the Western Roman emperor Flavius Honorius (reigned 393–423), Constantius helped to overthrow the usurping emperor Constantine (Flavius Claudius Constantinus) at Arelate (modern Arles, France). He drove the Visigoths from southern Gaul into Spain in 415 but later recalled the tribe and settled it in southwestern Gaul. In 417 he married the emperor’s half sister Aelia Galla Placidia. Appointed co-emperor of the West by Honorius, with the title augustus, on February 8, 421, Constantius died without having been recognized by the Eastern emperor, Theodosius II. Constantius’s son by Placidia ruled the West as the emperor Valentinian III from 425 to 455.

This article was most recently revised and updated by Encyclopaedia Britannica.