Očekivalo se da Maximus postane patricije umjesto Aecijusa, ali je to spriječio Heraclius. Tražeći osvetu, Maximus je dogovorio sa dva Aecijusova hunska prijatelja, Optilom i Thraustilom, da se izvrši atentat na Valentinijana III. i Heracliusa. [[16. mart]]a []., Optila je ubo cara u hramu dok je silazio sa konja u kampu Martius i spremao se za vježbe gađanja strijelom. Dok se iznenađeni car okretao da vidi ko mu je zabio nož, Optila je završio posao s još jednim ubodom oštrice. U međuvremenu je Thraustila ubio Heracliusa. Mnogi vojnici, koji su bili u samoj blizini događaja, su bili vjerni Aecijusovi pratioci i nisu pomakli ni prsta prilikom ubistva cara.
His final legacy has been similar to that of [[Stilicho]]. Both were the best Roman generals of their time, and both were killed by jealous emperors. Aëtius was a brilliant general but failed to look at how the map of Rome would stand later on. At the time of his death, not one province of Rome in western Europe was without a significant barbarian presence. After his victories he allowed the barbarians to stay inside the Empire's borders in exchange for peace, and their military service. He is also alleged to have failed to continue to develop Rome's navies, a significant problem for later emperors. That blindness, if true, was his greatest mistake. Simply put, he is alleged not to have seen the danger of Africa in barbarian hands. In that he would have been the only significant figure to have not foreseen that danger. Africa was the breadbasket of the Empire, and the source of most of the wealth remaining to the Western Empire. [[Edward Gibbon| Gibbon]] however is more kind to Aëtius, and believes his preoccupation with the Huns, more than not caring, limited his attention to the navy, and the subsequent loss of Africa. Emperors [[Majorian]], [[Leo I (emperor)|Leo I]] and [[Anthemius]] saw the necessity of Africa liberation. Even Visigoth puppet Roman emperor [[Attalus (emperor)| Attalus]] after sacks of Rome in 410 refused to give ships to barbarians for transport to Africa. Many historians feel Aëtius nominally preserved the peace and order, (in addition to his macrohistorical victory over Attila), but his reactionary stances left Rome ripe for its fall. It should be noted however that again, Gibbon, among others, disputes this. One fact however cannot be disputed. Even Gibbon agrees the reliance on barbarian troops was the primary reason for the ultimate fall of the Western Empire, and Aëtius certainly relied on them, to the detriment of the Empire when he was gone.
[[J. B. Bury]]'s assessment, however, was that the battle of Chalôns was fundamentally unimportant. Aëtius attacked the Huns when they were already retreating from [[Orleans]], so Gaul was not in immediate danger; and he declined to renew the attack, the next day, to preserve the balance of power. The important battle was three years later, when the Germans rose up against the Huns after Attila's death, and defeated them at the [[Nedao]], in []. This decided that there would be no Hunnic Empire, which Bury thinks would have been unlikely even they had crushed the Germans ''that'' time. In this light, Chalôns determined chiefly whether Attila spent his last year looting Gaul or Italy.