Europe 421: Constantius III

Flavius Constantius’ successful recovery of Gaul and Hispaniae (411–420) was followed by his acclamation as Honorius’ co-emperor in February 421. However, the elevation was immediately rejected by the Eastern Roman emperor Theodosius II and then rendered moot that September, when Constantius himself suddenly died of illness.

About this map

Download map
(download without labels)

This map has in-depth notes in the Journal, exclusive to Patrons on Classical Tier and above. Find them in the events descriptions, marked with the Journal icon .

Notes

Roman return to Britain

These maps show a Roman return to Britain in 418–421. There are a number of reasons to believe this might have happened, including:

A Roman return followed by an amicable withdrawal is mentioned by Gildas and Bede.
The Anglo-Saxon Chronicles date a Roman withdrawal to 418/421 and, along with Nennius, tell of departing Romans burying treasure that they did not take to Gaul. This is supported somewhat by the discovery of multiple 5th century hoards in south and east Britain.
There is evidence of work on Hadrian’s Wall dating to the 420s.
The Notitia Dignitatum, dated to the 420s in the West, attests to Roman units in Britain.
It makes logical sense for Constantius III’s forces to conclude their reconquest of Gaul in 418 by at least visiting Britain. It would also make sense that this visit would be unexpected and late in the year, as stated by Bede.
Continued interactions between the Roman church and Britain from the 420s to as late as the 450s suggest ongoing ties with the Empire.

However, be aware that at the present moment (2023) only a few mainstream historians hold this view. For further arguments in favor of a Roman return, see Pace (Nov 2015, Walls and Withdrawals: Gildas’ Version of the End of Roman Britain).

Main Events

420?–422 Armenian revolt▲

When, in 417, the Armenian king Vramshapuh died, leaving behind a son, Artaxias, who was still too young to succeed him, the Sasanian Persian Empire assumed direct rule over Armenia with the help of the the local Armenian nakharar nobility. By the beginning of the reign of Shah Bahram V (420–438), however, the Armenians had had enough and rose up against Persian rule. This revolt lasted three years, but was probably ended in 422, when the Persians agreed to enthrone a now-of-age Artaxias as King of Armenia. in wikipedia

420? Kidarite Kingdom▲

The aggression of the Central Asian Huns against Sasanian Persia increased during the reign of Shah Yazdegerd I (399–420) and eventually the Persians agreed to pay them tribute. By about the 420s contemporary sources had stopped referring to these Huns as the Chionites and were now calling them the Kidarites, probably simply in reference to the Chionite royal line of Kidara but potentially in response to a more significant change. Regardless, the Kidarites would soon encroach into both Persia and India, establishing a regional dominance that would last into the 450s. in wikipedia

420 Battle of Bracara Augusta▲

After the Romans helped defeat the Vandals in the Nervasos Mountains earlier in 420, a Roman contingent under the vicarius Maurocellus was attacked in Bracara Augusta (Braga) and narrowly escaped from the city. It is uncertain from the records who the attackers were in this encounter—especially as Bracara was in Suebic territory—but it is likely that this was part of a Vandal maneuver to evacuate Gallaecia and move south into Baetica. in wikipedia

420 Vandalusia▲

Following the battles of the Nervassos Mountains and Bracara Augusta in 420, the Vandals and Alans abandoned Gallaecia and moved into the wealthy southern Spanish province of Baetica. Here they would remain for most of the 420s, and it has been theorized since at least the 13th century that the region’s modern name, Andalusia, is derived from this Vandal settlement (perhaps from the Arabic al-Fandalus, the Vandals). in wikipedia

421? End of Maximus of Hispania▲

After their defeat in the Nervasos Mountains in 420, the Vandals fled south, apparently abandoning their puppet emperor Maximus in Gallaecia. Following this—by 421 at the latest—Maximus fell into the hands of the comes Hispaniarum Asterius, who promptly dispatched him to Ravenna. Here, in January 422, he was displayed as part of a ‘catalogue of usurpers’ during the celebration of Honorius’ tricennalia and then executed. in wikipedia

8 Feb–2 Sep 421 Reign of Constantius III▲

In February 421 the Western magister militum Flavius Constantius was elevated to the position of augustus, becoming Constantius III and co-emperor alongside the reluctant Honorius. Constantius’ wife—and Honorius’ sister—Galla Placidia was then acclaimed augusta and her son to Constantius, Valentinian, declared nobilissimus puer (most noble child). All these pronouncements were promptly rejected by the Eastern emperor Theodosius II, which might have led to a Roman civil war had not Constantius fallen ill and died, probably of pleurisy, that September. in wikipedia