The ‘Barbarians’ Who Saved & Destroyed the Late Roman Empire

When one pictures the Roman Empire, it can be quite easy to conjure up images of its glorious and all-conquering heydays. Visions of Caesar’s conquests, the civil war, Augustus, or the golden age of the Antonines. Throughout these portrayals, the primary enemy of the civilized Roman was the ‘barbarian,’ usually a Gaul, Scythian, or German.

However, while these periods make for good cinema or television, there exists an era infinitely more dramatic and turbulent, just under the radar of modern media’s glare. Between the late 4th and 5th centuries, the Roman emperors were often weak and incompetent puppets. Instead, the empire’s lifespan was extended and ultimately extinguished by a succession of ‘barbarian’ generals from beyond the imperial frontiers. This article tells the tale of how these ‘barbarians’ came to rule the fate of the Late Roman Empire.

As the Republic and early Empire expanded its territories throughout Western Europe and the Mediterranean basin, they gradually overcame every foe they encountered. Through cunning, diplomacy, or brute force, the peoples of the classical world fell under the hegemony of the Romans, all except one. Caesar conquered Gaul and, according to Plutarch’s Life of Caesar (58,6), had planned to return to conquer Germania after his Parthian campaign in the east. After Caesar’s death, the first emperor, Augustus, endeavored to subdue the untamed Germans and their dark forests but lost three legions, and his territorial aspirations, at the ambush of Teutoburg. Augustus warned his successors to maintain the empire within the boundaries he had set.

Eventually, at the height of imperial prowess, under the philosopher-emperor Marcus Aurelius, a new German province of Marcomannia was planned. Though his son, Commodus, soon abandoned any such ambition, whether out of idleness or preoccupation. So, the Danube and Rhine rivers remained the barrier between the Latin and Teutonic worlds. These worlds certainly interacted, with German men often serving as mercenaries in the legions and trading with Roman commerce. Throughout the civil wars of the 3rd century, the Germans regularly took advantage of the weakened and fragmented imperial state. However, by the mid-4th century, a new state of affairs had arisen, one which would come to inextricably link these two peoples indefinitely.

II: The House of Constantine  

On the 26th of July, 306 CE, the Caesar Constantius died in Eboracum, modern York. Constantius was the first of the four Tetrarchs to pass, and with his death began the unraveling of the system of imperial power-sharing orchestrated by Diocletian to end the 3rd-century crisis. Constantius supposedly named his son, Constantine, his successor with his final breaths, breaking the Diocletianic precedent of appointed, rather than an inherited, succession. Constantine’s ascension to the rule of Britain, Gaul, and Spain marked the start of a period of further civil wars, which would culminate, in 324 CE, with his sole rule of the Roman world, which would last until 337 CE.

Emperor Constantine’s two most consequential actions in his reign were to construct the city of Constantinople at the crossroads of Europe and Asia, and to begin the Christianization of the empire. Like his later Frankish admirers, on his death, Constantine divided the empire among his three sons who, like their father, inevitably sought the sole rule of all his domains. The eventual victor of these contests emerged as Constantius II, a paranoid and short-tempered man who butchered most of his male relatives to secure his position. Eventually, and without bloodshed, Constantius was succeeded by his nephew Julian, a self-styled ascetic and worshipper of the pagan gods. Though he began to push back the tide of monotheism sweeping the empire, his reign was brief. He was killed (363 CE) in an ill-fated campaign against the Sassanid empire, trying to imitate his idol, Alexander the Great, and sealing the empire’s now Christian fate.

For our narrative, the main importance of the rule of Constantine I and Constantius II is that under their stewardship, the military became increasingly dominated by men of German origin, whilst imperial courts became increasingly concerned with Christological and ecclesiastical debates. The use of auxiliary troops from beyond the frontiers was nothing new to the Roman army. Caesar would not have been able to raise as many legions as he did without the freshly levied Gauls and Germans. However, Constantine’s motives were political as well. Those of Germanic, rather than purely imperial, descent would always have a weaker claim to legitimate imperial rule, and so the men in charge of the largest armies would be less likely to usurp his throne. This trend was further compounded by the lack of imperial recruits into a military that faced increasingly difficult threats. Initially composed of Italian recruits, the legions had seen their compositions alter drastically as the empire grew.

After the Republican civil wars, a large part of the legions came from Gaul and Spain. After the Severan civil wars, the Illyrians and Syrians came to the fore. Now the German troops, from outside the imperial boundary would come to dominate the Roman army. First, through German mercenaries serving under Roman generals, then through whole armies serving under their own tribal commander and in the employ of Rome, known as foederati (federated troops). This gave the army fresh strength and vigor but also trained the Germans in the ways of Roman warfare, should they ever choose to fight their imperial paymasters. At some point between Diocletian and Constantine, the office of Magister Militum was created as a sort of Field Marshal for the Roman Legions. As we shall see, the holders of this office would be primarily German in the 5th century and wield great power.

Another key event of Constantius II’s reign was the Battle of Mursa Major. A battle between the armies of the east and the west which had such a high death toll that Eutropius (Book X, XII) and Zosimus both accredit it as one of the worst catastrophes for the empire. They claim it weakened its power irreversibly, further requiring the manpower of the Germans and limiting the empire’s ability to protect its frontiers. This pyrrhic victory for Constantius was yet another Roman civil war that left more than 50,000 Romans dead and unable to man the frontiers.

After Julian’s death in Persia, the army chose a little-known junior officer, Jovian, to lead them back to the safety of imperial territory. To do this, he had to conclude a humiliating peace treaty with the Sassanids. Not long after this, he was found dead in his quarters, though no foul play was suspected. Again, the army chose a little-known junior officer, Valentinian. This hardy Dalmatian soon recognized the empire was ungovernable by one man, apportioning to himself the Western sectors while assigning his brother Valens the eastern provinces. The brothers’ reigns were primarily spent repelling frontier incursions and minor usurpations until, after the death of Valentinian, a deluge would be unleashed upon his brother and his son. This would mark the beginning of the final decline of the empire in the west and its transformation in the east.

This deluge was part of a cascade whose origins will be discussed later in the form of the Huns. As these steppe nomads moved east, the Gothic tribes dwelling in the Black Sea region around modern Ukraine were forced westwards into the lands of the Eastern Roman Empire. An agreement was reached with Valens to resettle this Gothic nation within the empire so that they could plow the fields and man the frontiers. Their migration across the Danube was scarred by Roman mismanagement and corruption, which eventually led to the Gothic people revolting against their abusive host. Their leader, Fritigern, had a large enough army to give him free reign over the Thracian countryside.

Messengers were dispatched to the Western empire for assistance as Valens returned from the eastern frontier with a force large enough to confront Fritigern. The Western emperor, Gratian, had begun moving to the aid of his uncle, but was postponed by a barbarian incursion over his own frontiers. Ammianus (XXXI, X) says that a German soldier in Gratian’s army slipped across the frontier to inform his old tribe that his new emperor was moving most of the Western army eastward. This sparked an opportunistic raid that slowed down the young emperor. This delay caused Valens to take unilateral action against the Goths, perhaps also out of a desire not to have to share the glory of victory with his young nephew.

The proceeding Battle of Adrianople (378 CE) essentially left the Eastern empire without an army or an emperor. While the opposing armies were locked in combat, the Gothic cavalry returned from a foraging trip, a damning failure on Valens’ reconnaissance units. The entire Roman army was surrounded and cut down while Valens himself unsuccessfully tried to escape. Gratian scrambled to find a competent eastern ruler, settling on Theodosius, an eastern Duke of Spanish origin. Theodosius recognized that without an army, confronting the Gothic nation would be suicidal. Instead, a compromise arrangement was reached under which the Goths would reside as a nation, within the safety of the empire, in exchange for foederati military service if called upon, which they would be. By the end of Theodosius’ reign, the German monopoly on power in the empire was near complete.

Theodosius was aided by his Gothic allies to defeat the murderer of Gratian. After Magnus Maximus was killed, Theodosius left the Frankish general Arbogast as Magister Militum in the West, as a steward for the young Valentinian II. It soon became apparent that Arbogast would not be ceding any of his power to the young emperor, and after a number of disagreements, the boy was found hanged in his chambers. Like Constantine had planned, Arbogast, as a German, could not legitimately rule his portion of the empire. However, he chose to rule through a puppet emperor, Eugenius. Both were defeated at the Battle of the River Frigidus by Theodosius. This battle was notable for Theodosius’s callous employment of Gothic lives, and the vendetta that would be held by their young king, Alaric, as a result.

Theodosius did not live long to see the fruits of his victory, and though he united the empire in 394 CE, the following year saw it divided between his two sons. The boys Honorius, in the West, and Arcadius, in the East. Theodosius died in Milan before there was time to return the eastern army to Constantinople. Therefore, the half-Vandal (German), Flavius Stilicho, new Magister Militum of the West, was left as the most powerful man in the empire. What followed was a series of complex political and military machinations that weakened both halves of the empire.

The scorned King Alaric led his Goths eastward and began pillaging the Balkans en route. Stilicho pursued and cornered him. However, having violated Eastern territory, he was ordered by the Eastern court to return its share of the imperial army. Arcadius had been left in Constantinople by his father and had fallen under the sway of its influential courtiers. Principally the general Rufinus and the eunuch Eutropius. When Stilicho sent the Eastern army back, its Gothic general, Gainas, murdered Rufinus outside the walls of Constantinople. Gainas and Eutropius then competed for power in the East, with the eunuch eventually outmaneuvering the Goth.

Rather than have him continue his Balkan pillaging, Eutropius appointed Alaric as the Eastern Magister Militum, setting him against their new public enemy, Stilicho. The imperial cold war was heating up. For the next decade, Stilicho protected the Western Empire and its emperor from Germanic incursions across the Rhine and Danube. He also repeatedly fended off Alaric and his Goths, acting as proxies for the Eastern Court.

Through mutual respect, Alaric and Stilicho came to an agreement in 406 CE to seize Illyricum from the Eastern empire and settle it with Goths. This would have benefitted both men and created an alliance. However, Vandal incursions over the Rhine and a revolt in Britain delayed Stilicho. Alaric still demanded his pay upfront, which Stilicho persuaded the senate to agree to. This sealed Stilicho’s fate, as the Western court convinced Honorius that this half-German Roman general was in league with the Gothic enemy. Honorius ordered the death of the only man keeping his empire from anarchy, along with any Goth that could be found.

In the space of two years, the Western Empire went from nearly securing a Romano-Gothic alliance to the sack of Rome (410 CE) by those very Goths. Once the half-German protector Stilicho was removed, the weakness of the West was abused by Alaric. The eternal city saw its first sack and occupation by a non-Roman army in eight centuries. A degree of order was achieved by the Roman general Constantius, who was made co-emperor by Honorius in 421 CE and married into the imperial family. Dynastic marriage ambitions had been another cause for aristocratic animosity among the half-Vandal Stilicho. Constantius III died in 421 CE and Honorius followed in 423 CE. The power vacuum opened by their deaths began the next German power struggle within the empire.

Honorius’s only redeeming feature was his lineage. Once he was dead, the powerbrokers in the Western Empire sought to replace the Theodosian line with Joannes. This high-ranking officer had powerful support amongst the Western foederati and senate. In particular, a young officer, Flavius Aetius. Aetius was of Scythian origin but had spent large parts of his youth either as a hostage with German or Hunnic tribes beyond the frontier. As a result, he had amassed a large following of foederati, which he planned to bring to Joannes’s aid. Before he could reach Ravenna, the German forces of the Eastern Empire under Ardaburius and his son Aspar installed Valentinian III and his mother. They held dynastic legitimacy, but Aetius commanded the largest army. Therefore, after the regular court intrigues, an uneasy compromise was reached, investing him as Magister Militum of the West. This was also because Aetius proved to be the only man capable of stopping the Hunnic tide that was now crashing against the empire. Edward Gibbon famously called him ‘the last Roman’, as he was able to save the empire from oblivion.

The nomadic Huns had been steadily moving eastward for decades, likely from Central or Eastern Asia. Gradually a confederacy had formed to exploit the static civilized empires, and Attila now ruled this Hunnic ‘empire’, including many German vassals. The Hunnic expansion had caused migratory pressures amongst other Germans into the empire in the late 4th and early 5th centuries. The Eastern court had long been extorted by these nomads but in 449 CE Attila set his sights on the West. Aetius managed to create an alliance of Romans, Visigoths, Franks, Saxons, and smaller German tribes to meet Attila in Gaul.

The Battle of the Catalaunian Plains (Chalons) 451 CE was the final burst of strength from an empire on its knees. It was won primarily by German foederati under a half ‘barbarian’ general. As thanks for this victory, the paranoid emperor Valentinian III personally killed Aetius (453 CE), as he saw him as a potential rival. The Bishop Sidonius Apollinaris quipped to the emperor that ‘you have cut off your right hand with your left,’ and with Aetius went any martial vigor left in the Western empire. Not long after this act, Valentinian was butchered while on a hunt by Huns loyal to Aetius.

After Aetius, the Western Empire accelerated into its final collapse. As with Stilicho, within two years of his death, Rome had been sacked by a Germanic people. This time the Vandals in 455 CE from their Kingdom in Africa, the fleeing emperor killed by an angry mob of Romans. Following this, the German Visigoths proclaimed the Praetorian Prefect, Avitus, but his vassalage was obvious, and his legitimacy challenged.

Again, another high-ranking Romano-German general rose to prominence to lead the empire and again through puppet emperors. Flavius Ricimer deposed Avitus in favour of his friend, the officer Majorian. Together they failed in an attempt to retake North Africa from the Vandals. Ricimer replaced Majorian and oversaw three more disastrous reigns before his death. By now, the empire in the west consisted of little more than the Italian peninsula.

The Eastern Roman Empire had seen a barbarian power struggle of its own. The Germanic Magister Militum, Flavius Aspar, who had installed Valentinian III, now faced a challenge. A court faction had emerged in Constantinople; the Isaurians. The Isaurians, though originating from within imperial territory, were hardy mountain folk, seen as uncouth barbarians by the Roman aristocracy. The Isaurian, Zeno, replaced Aspar as Magister Militum and eventually ascended to the throne. Zeno was the emperor at the time of the fall of the West, and so his reign begins the early Byzantine period.

Zeno received the Western imperial insignia from the Gothic general Odoacer in 476 CE. Odoacer had deposed the minority Western Emperor while the last legitimate claimant languished in Dalmatian exile. The German general then chose to rule Italy as Rex (King), leaving the imperial ambition to the court of Constantinople. The East became increasingly a Greek empire, with its last native Latin speaking emperors reign, Justinian, ending in 565 CE, less than a century after the fall of the West.

The remnants of the West became the barbarian successor kingdoms, ruled by Germanic chieftains turned feudal kings. They maintained Roman culture to varying degrees. The finest example of a Romano-German ruler was surely Theodoric the Amal. A German, educated and raised in Constantinople, he led his Goths into Italy to retake the peninsula for the emperor Zeno. He was then granted the Western imperial insignia and the title patrician and Augustus but ruled Italy only as Rex for Zeno. He expanded into Spain and Gaul while maintaining the dignity of the Roman senate. His main blemish was the imprisonment and execution of the senator Boethius.

So ended the Roman Empire in the West and began the transformation of the East. Since the Republic’s earliest days, the Romans had been aware of other peoples they deemed as barbarians, from the Greek word barbaroi. They had often looked down on these savages, perceiving them as unfit and unable to reside in a civilized society. However, since the rule of Constantine the Great, the influence of these outsiders steadily grew. Where weak emperors would have fled, these ‘barbarians’ stood firm and saved the empire. Stilicho and Aetius saw the empire through some of its darkest days, and their deaths left the Roman West without light. Inevitably, like the Romans, the barbarians found themselves unable to rule such a vast and assailable polity. By the time the empire collapsed, a link had been forged between the Teutonic and Latin peoples that would last a further millennia.