What was the Battle of Adrianople?

Short answer

The Battle of Adrianople (August 9, 378 CE) was a major battle in which a Roman army under Emperor Valens was defeated and largely destroyed by an army of Visigoths. The battle was one of the worst military disasters in Roman history and is often cited as one of the key turning points in the fall of the Western Roman Empire.

A longer answer

The Battle of Adrianople took place on August 9, 378, near the modern city of Edirne in European Turkey, then the Roman city of Adrianople. The Roman army, led by the emperor Valens, was defeated by a much larger force of Visigoths, Sarmatians, and Ostrogoths under the command of the Visigothic chieftain Fritigern. The Roman army was annihilated. Two-thirds of the field army was destroyed, and the emperor Valens himself was killed, his body never recovered. The disaster shocked the entire Roman world.

The background

The background to the battle lay in the great movements of peoples triggered by the Huns. In the late fourth century, the Huns were moving westward across the Eurasian steppe, pushing the various Germanic peoples ahead of them. The Visigoths, an East Germanic people, were the first to be pushed into Roman territory. In 376, they crossed the Danube into the Roman Empire, asking for asylum. The Roman emperor Valens allowed them to cross, on condition that they give up their arms and accept Roman rule.

The terms of settlement were harsh, and the Roman officials who administered them were often corrupt. The Visigoths were soon in revolt. They defeated a Roman army at the Battle of Salices in 367, and they rampaged through the Balkans for the next two years. In 378, Valens himself marched against them, but his campaign was poorly planned and he was further weakened by the absence of the Western Roman emperor Gratian, who was marching to his aid with reinforcements but had not yet arrived.

The battle

On August 9, 378, Valens engaged the Visigoths near Adrianople. The Roman army was about 20,000 strong, mostly infantry, with a small cavalry force. The Visigoths were probably 20,000 to 30,000 fighting men, but they were reinforced by Ostrogothic and Sarmatian allies. The battle began with a Roman cavalry charge that was repulsed, and then the Visigothic cavalry, perhaps 5,000 to 10,000 strong, executed a flanking maneuver that encircled the Roman infantry. The Roman army was surrounded and destroyed.

The emperor Valens was killed during the battle, possibly in the burning of a wooden building in which he had taken refuge. His body was never recovered. The defeat was total: the eastern Roman field army ceased to exist as a fighting force, and the Balkans were left open to the Visigoths and other Germanic peoples.

The aftermath

The defeat at Adrianople was a turning point in Roman history. The eastern Empire was unable to reconquer the Balkans, and the Visigoths were eventually settled within the Empire as foederati, allied troops under their own leaders. This settlement, in 382, set a precedent that would be followed with other Germanic peoples in the fifth century. Within a few decades, large groups of Visigoths, Vandals, Ostrogoths, and others would be settled within the Empire, often with their own kings and their own laws, and they would become one of the major causes of the fall of the Western Roman Empire.

The Battle of Adrianople also revealed the military weaknesses of the late Roman army. The Roman infantry, which had been the backbone of the army for centuries, was now vulnerable to massed Germanic infantry and Hunnic horse archers. The traditional Roman tactics, designed for a Mediterranean battlefield, were no longer adequate against the new tactics of the steppe and the forests. In the aftermath of Adrianople, the Roman army increasingly relied on Germanic foederati and on cavalry rather than infantry, a transformation that would change the character of Roman warfare for the rest of antiquity.

The historical significance

The Battle of Adrianople has been the subject of extensive historical debate. The Roman historian Ammianus Marcellinus, the principal source for the battle, blamed Valens for the disaster, accusing him of pride, impatience, and bad generalship. Modern historians have generally agreed, but they have also pointed out the structural problems of the late Roman army, the increasing difficulty of defending the long Rhine-Danube frontier, and the unprecedented scale of the Germanic migrations.

The battle is often cited, alongside the sack of Rome in 410 and the deposition of Romulus Augustulus in 476, as one of the key turning points in the fall of the Western Roman Empire. While 476 is conventionally used as the end of the Empire, the process that produced the fall arguably began in the late fourth century, and Adrianople is one of the major markers of that beginning. The historian Peter Heather, in The Fall of the Roman Empire (2005), has argued that Adrianople and the related events of the late fourth century set in motion the chain of events that would eventually destroy the Western Empire.

Conclusion

The Battle of Adrianople in 378 CE was one of the worst military disasters in Roman history. The destruction of the eastern Roman field army and the death of the emperor Valens marked a major turning point in the late Roman world. The Visigoths and other Germanic peoples would continue to enter the Empire in the years that followed, and the precedent of settling them as foederati would eventually contribute to the fall of the Western Roman Empire in the fifth century.