The battle of Hadrianople was fought on August 9 (A.D. 378); the leader of the Goths was Fritigern; the Romans were commanded by Emperor Valens himself. Valens made the great error of under-estimating the enemy. He was jealous of the military reputation of his nephew and colleague Gratian, a young man who had succeeded his father Valentinian I as a ruler in the west, and had just gained a signal victory in a war against the Alamanni. Gratian was at the moment marching to help his uncle to crush the Goths, and implored him to take no risks till he arrived and they could meet the enemy with combined forces that would ensure victory. Valens decided not to wait but to win all the glory for himself. The battle resulted in the utter defeat of his legions and his own death. It was a disaster and disgrace that need not have occured.
It is described at length by Ammianus, but it is curious and very dissapointing that, though the historian was a soldier himself, he did not tell his readers definitely the number of forces on either side. So that we do not know precisely how strong the Goths were, or how strong were the Romans. The point I would emphasise here is the importance of the battle in military history.
Hitherto in warfare the Romans had always depended on their infantry. It was their main arm, and in regular battles the cavalry was always considered subsidiary and auxiliary to the legions. Other things being equal, the well trained legions were almost invincible. In this battle the legions had the novel experience of being ridden down by the heavy cavalry of the German warriors. This was a lesson which showed what cavalry could do; and it had influence on all subsequent warfare. Between the fourth and the sixth century there was a revolution in the character of the Roman armies and Roman warfare. In the fourth century infantry was the arm on which the Romans still mainly relied, and with which they won their victories in the open field; whereas in the sixth century infantry played a small part in their battles, and victories were won by cavalry. For both these centuries we have detailed descriptions of battles, so that there is no doubt on the question, and these descriptions come from exceptionally good sources, from Ammianus in the fourth and from Procopius in the sixth. Now for the intermediate period, the fifth century, we have not a single good account of any battle written by a contemporary, so that we are not able to trace the change. But it is clear that in the course of that century this change must have come about, to meet the tactics of the East Germans with whom there was a constant warfare.
This is a point of considerable interest because until quite late in the Middle Ages, both in the west and east, it was cavalry and not infantry with which battles were fought and won. In the fourteenth and fifteenth centuries warfare was again revolutionised by the Swiss pikemen and English archers, who demonstrated that footmen could succesfully oppose heavy horse.
After their signal triumph in the field the Goths besieged the city of Hadrianople, which they looked forward to capturing easily and plundering. They could not, however, take it; but the open country of the provinces of Thrace was exposed to their depredations for a couple of years. The war was then brought to an end, and there was a general pacification of the Goths. This was achieved through the military activity and the skilful diplomacy of Theodosius the Spaniard, who was coopted Emperor by Gratian at the beginning of A.D. 379 to take the place of the defunct Valens. The chief obstacle to a peaceful arrangement was Fritigern, who stands out in this episode as the moving anti-Roman force. He desired to wrest provinces of the Empire entirely away as his predecessors had wrested Dacia, and to found an entirely independent Gothic state south of the Danube. After his death, however, the Visigoths were induced, through the successes and skilful dealings of Theodosius, to become subjects of the Emperor -not regular provincials and Roman citizens, but allies on a footing of freedom and semi-independence, still remaining a nation but owing definite obligations to the Emperor. Lands in the province of Lower Moesia, the modern Bulgaria, were assigned to them- the same region in which Constantine had settled their Christian fellow countrymen whom Wulfilas had led out of Dacia. They were to pay no tribute for the land; they were to receive certain pensions from the government; but they were to serve the Empire when needed as federate soldiers under their own chief. The capitulation was concluded in October 382.
In the future shaping of Europe, this series of events had considerable importance:
i) The reception of a whole people within the borders of the Empire, as federates, marks a new stage in the process of German encroachment. It strikes what was to be the characteristic note of the dismemberment of the Empire, namely, disintegration from within
ii) A new destiny is heralded for Dacia and the lands between the Carpathians and the Danube. Dacia had passed from the Dacians to the Romans, from Romans to Teutons; it is now to pass under the rule of the Huns, and the Hun is the forerunner of other non-European conquerors and lords, first the Avars and afterwards the Magyars.
iii) The Gothic people, which had long ago been politically split up into Visigoths and Ostrogoths, becomes now permanently divided. They are parted for ever, each to go its own way; they will never again have to face Rome together
It was much later before the Ostrogoths began to play an important role in history; but they were to some extent mixed up in the troubles of these years. Driven before the Hun, some considerable bands crossed the Danube near its mouth and added to the confusion and disturbances in Thrace. They were defeated by Theodosius, and he, pursuing the same policy as he pursued with the Visigoths, settled them on imperial soil as federates. Not, however, on the frontier, nor in the neighbourhood of the Visigoths, nor even in Europe; he transported them to Phrygia in Asia Minor. They were, however, only a fragment of the nation, of which the greater part seems to have moved westward towards the middle Danube and the frontiers of Pannonia.
(Source: “The Invasion of Europe By the Barbarians”, by Bury, J.B.)
Research-Selection for NovoScriptorium: Anastasius Philoponus