Flavius Aetius (396-454), The Last of the Romans

On September 21, 454, Flavius Aetius, Roman general famous as the victor at the Battle of the Catalaunian Plains, was assassinated by Valentinian. From the article:

"Aetius’s greatest military victory is that of Châlonssur-Marne, also called the battle of Maurica or Campus Mauriacus, or the battle of the Catalunian Plains. On 20 September 451, Aetius, commanding groups of barbarian soldiers, including Visigoths and Burgundians— both of whom he had previously defeated—faced Attila and the Huns, Aetius’s former allies. Attila had turned against the Roman Empire to rampage across Rome-controlled Europe, devastating the Balkans and exacting tribute from the Eastern Roman Empire. When the Huns turned on Gaul, Western Roman emperor Marcian called on Aetius to defeat his former allies. At Châlons-sur-Marne, Attila gathered the forces of many barbarian tribes, including the Ostrogoths, the Gepids, the Thuringians, and the Franks. To start the battle, Aetius dispatched Thorismund, the son of King Theodoric of the Visigoths, and his forces to seize an area that overlooked the whole field; Thorismund battled back the Hunnic forces to take the area. The Huns joined the Ostrogoths to assault the main Visigothic regiment, but the Visigoths held despite the death of King Theodoric. A contingent of Gepids attacked a position held by Romans and Franks, but they, too, could not break through. The battle lasted throughout the day; it is estimated that perhaps 300,000 men died, although many historians dispute this number. The end of the fight came when, in the darkness, Thorismund and his men charged down the hill from the heights he had seized and drove the Huns and Ostrogoths into flight."