Warmatrix

Maps of the Battle of the Catalaunian Plains

The Battle of the Catalaunian Plains, a.k.a. the Battle of Châlons or the Battle of Maurica was fought 451 CE. In it, a coalition of Romans and barbarians managed to stop the westward expansion of the Huns, led by Attila. But it was not a complete success and the Huns continued to plunder Gaul. They were decisively beaten three years later at the Battle of Nedao. Tellingly, there it was Germanic barbarians who did most of the job, with only a small Roman force partaking. The Battle of the Catalaunian Plains was the last time that the western Roman army fought a large battle.
At the time of the battle Gaul was a mix of pure Roman territory, barbarian vassal states and semi-independent kingdoms. The Huns had a base in the Great Hungarian Plain, from where they could strike into most of Europe. There are several stories that explain why Attila wanted to attack Gaul, though none can be verified, so maybe it was no more than a desire for plunder. The Huns crossed the Rhine early in the year and sacked most major cities in northern Gaul. Only the Alans in Aurelianum (modern Orleans) refused to submit and forced them to start a siege. This siege was probably more important than the following field battle.
The Roman commander Flavius Aetius, who had lived a few years among the Huns, moved into Gaul from Italy, but brought few troops with him. He managed to convince Theodoric I, king of the Visigoths, to come to his aid. Many other tribes also joined in: Franks, Burgundians, Saxons and more. The Huns too were a mixed force, fielding the Huns themselves but also Gepids, other Burgundians, Thuringians and others. There are no reliable numbers on the sizes of the armies. Estimates in the historical accounts are ridiculously high and modern estimates are all indirect.
The western allies approached Aurelianum, where the walls were starting to break. Hearing that a relief army was coming, Attila broke off the siege and retreated. The two armies clashed on the Catalaunian Plains. The battle started late in the day, possibly because both sides spent a lot of time lining up. The westerners deployed the Romans and Franks on the left, Alans in the center and Visigoths on the right. The Huns occupied their own center, with Ostrogoths on the left and Gepids plus Germans on the right. The plains were dominated by a steep ridge, which became the center of the battle. The Huns pushed back the Alans and got into a position where they could either strike left or right. But the Romans and Franks pushed back the Hun right and the Visigoths managed to seize the hilltop first. From there their cavalry launched a charge on Atilla's household troops. Threatened with encirclement, Attila hastily withdrew to his camp. When night fell, the situation became chaotic and units of both sides lost contact with each other. Thorismund, son of Theodoric, pursued the Ostrogoths too far, mistakingly entered the Hunnish camp and was wounded.
The next day the Romans and Visigoths besieged the Hunnish camp for a while, knowing that their enemy was low on supplies. During the battle king Theodoric had died. According to one story, Aetius convinced the Visigoths and Franks to retreat to sort out their own troubles at home. He may have hoped to employ the Huns later as mercenaries against the other barbarians. This move broke the siege and allowed the Huns to retreat also.
The Battle of the Catalaunian Plains is heralded by some as the event that finally stopped the Hunnish threat, but their subsequent continuation of plundering shows that it did not. Only when Atilla died and the Huns turned upon each other, were they really weakened. The battle is most interesting in that it shows the weakness of the western Roman empire at the time and how important the barbarians had become.