Constantius (Latin: Flavius Constantius Augustus) (died 2 September 421), commonly known as Constantius III, was Western Roman Emperor for seven months in 421. A prominent general and politician, he was the power behind the throne for much of the 410s, and in 421 briefly became co-emperor of the Western Empire with Honorius.
Early life and career
Consular diptych of Constantius III, produced for his consulate in 413 or 417.
Constantius was born in Naissus (modern-day Niš, Serbia) and was probably a career soldier, who reached the rank of magister militum under Honorius.
Constantius avenged the killing of his friend and previous magister militum Stilicho by having Olympius, the principal instigator Stilicho's assassination, clubbed to death in 410/11.
Defeating rebellions, 407-411
In 406, a mixed band of Alans, Sueves, and Siling and Asding Vandals crossed the Rhine and invaded Roman Gaul, meeting little or no resistance from the Italian-based government. Probably in response, Constantine, the Roman commander in Britain, rebelled against Honorius in 407 and declared himself Emperor. In 409, Constantine's general Gerontius in Spain proclaimed Maximus Emperor in opposition to both Honorius and Constantine, and invited the four invading tribes to migrate to Spain, which they entered in October 409. Gerontius besieged Constantine in the city of Arles in 411, but the arrival of Constantius and the imperial army from Italy made the besieger a besieged. Gerontius, abandoned by his soldiers, was killed in Hispania.
Constantius then besieged the city himself for three months while Edobichus, another of Constantine's generals, was sent across the border to find allies. He returned with a large army of Franks and Alamanni to reinforce Constantine's forces within the city. Before the walls of Arles, Constantius confronted and defeated Edobichus, who was later betrayed and killed by a friend. Constantine was forced to surrender to Constantius. Constantius granted Constantine safe conduct, and the usurper was later ordained as a priest; nevertheless, he was eventually executed on the orders of Honorius.
Rise to power
In 413 Contantius was appointed consul for the first time. In 414 he began a military offensive against the Visigoths, who had moved out of Italy in late 412 to southwest Gaul. Ataulf, leader of the Visigoths, elevated Priscus Attalus as emperor for the second time (the first had been just before the sack of Rome in 410 in a vain bid to attract support). Constantius cut off the supplies to the Visigoths in a blockade of ports that was so effective that the Visigoths moved from Gaul to Hispania in 415. Attalus too tried to flee but was captured by the forces of Constantius and sent to Ravenna. After the death of Ataulf and his successor Segeric the same year, the new king Wallia agreed to terms. The Visigoths accepted 600,000 modii of wheat from the Romans; a modius weighed variously between 13.5-15 pounds, so this was enough for 3 to 4 months for 100,000 persons, probably to make bread while they were moved from Spain to Gaul or prevent starvation. In return, the Visigoths pledged to settle in land assigned to them in Aquitaine between the Pyrenees to the Garonne, and to fight on behalf of the Romans as official treaty allies of the Empire (foederati). The agreement also provided for the release of Galla Placidia, Honorius' half-sister, captured during the sack of Rome in 410. The Visigoths promised to attack the four tribes that had invaded Gaul, which they did: they almost destroyed the Alans and Siling Vandals and confined the Sueves and Asding Vandals to Gallicia in northwest Spain. Why they were not allowed to finish the job remains a mystery.
Constantius was appointed patricius, and in 417 consul for the second time with Honorius as colleague. He married Galla Placidia and with her had two children, Justa Grata Honoria (born 417/418) and the future Emperor Valentinian III (born 419). In 420 he was appointed consul for the third time, with the Eastern Emperor Theodosius II as colleague.
Brief reign and death
On February 8, 421, Constantius was appointed co-emperor with his ineffectual brother-in-law, Honorius, becoming the real master of the West. Curiously, he complained of the loss of personal freedom implied by the new role. The elevation of Constantius, however, was not recognized by his colleague in the East, Theodosius II, who was the nephew of Honorius.
It is said that Constantius was organizing a military expedition to the East to have his rights recognized when he died suddenly on September 2, 421, after just seven months as emperor, the archetype of able soldier and politician that the Western Roman Empire desperately needed at the time. A struggle to replace Constantius swiftly erupted, with some open fighting. Galla Placidia fled with her son Valentinian to Constantinople. Her brother Honorius, still childless, died in 423.
Constantius' success in rising from head of the Roman army to emperor was a facilitated by the fact that he was a Roman while Flavius Aëtius was a Goth or Scythian on his father's side and Ricimer was Sueve on his father's and Visigoth on his mothers. Though both men were Romanized their ancestry made them ineligible to be emperor. Other usurpers were Roman.