In Gaul, Aëtius defeated the Visigoths at Arles, forcing them to return to Aquitaine. He then proceeded to reinforce the Rhine frontier and defend Noricum against German attacks. Meanwhile, in Africa, Count Boniface fell into disfavour with Placidia, perhaps partly due to the intrigues of Aëtius and other Roman generals.
Boniface was eventually returned to favour by Placidia, not before revolting in Africa and calling in the Vandals. In 432, Boniface was recalled to Italy and given the rank of patrician. Aëtius, believing that Placidia had decided to get rid of him, marched against Boniface and fought against him in a battle near Rimini. Boniface won the battle tactically but was mortally wounded and died a few months later. Aëtius escaped to Dalmatia, and, with the help of the Huns (for which they were rewarded with territory in Pannonia), was restored to power by Placidia in 433.
From 433 to 450, Aëtius was the dominant personality in the Western empire. He continued to devote his attention to Gaul after his restoration to power. In 436, the Burgundians, taking advantage of disturbances caused by Bagaudae (bands of rebellious peasants, slaves and bandits), tried to seize more territory. Aëtius responded by calling upon the Huns to intervene, and 20,000 Burgundians were killed in a slaughter which became the basis of the Nibelungenlied, a German epic. In 443, Aëtius settled the remaining Burgundians in Savoy, south of Lake Geneva. His most pressing concern in the 440s was with problems in Gaul and Spain, mainly with the Bagaudae. He settled Alans around Valence and Orleans to contain unrest around present-day Brittany.
In 451 a large army of Huns, led by Attila, invaded Gaul and captured several cities, and proceeded towards Orleans. One of the great achievements of military history was the assembling of the coalition against Attila. Arthur Ferrill, addressing this issue, says
When the Alans living in the region were ready to defect to Attila, Aëtius and the Visigothic king Theodoric I moved in to relieve the besieged city of Orleans. The Huns abandoned the siege and retreated to open country, where, on September 20, 451 (some sources place the date at June 20, 451), they and their allies battled the Romans and Visigoths, along with their Alan, Frankish, and Burgundian allies, on the Catalaunian Fields near Châlons-en-Champagne. Although tactically the outcome of the battle was indecisive, it was a great triumph for Aëtius and the Romans. Attila was forced to retreat beyond the Rhine, though he returned once more to Italy.
Attila returned in 452 to again press his claim of marriage to Honoria, invading and ravaging Italy along the way; his army sacked numerous cities and razed Aquileia completely, leaving no trace of it behind. Valentinian fled from Ravenna to Rome; Aëtius remained in the field but lacked the strength to offer battle. Gibbon however says Aëtius never showed his greatness more clearly in managing to harass and slow Attila's advance with only a shadow force. Attila finally halted at the Po, where he met an embassy including the prefect Trigetius, the consul Aviennus, and Pope Leo I. After the meeting he turned his army back, having gained neither Honoria's hand nor the territories he desired.
Maximus expected to be made patrician in place of Aëtius, but was blocked by Heraclius. Seeking revenge, Maximus arranged with two Hun friends of Aëtius, Optila and Thraustila, to assassinate both Valentinian III and Heraclius. On March 16, 455, Optila stabbed the emperor in the temple as he dismounted in the Campus Martius and prepared for a session of archery practice. As the stunned emperor turned to see who had struck him, Optila finished him off with another thrust of his blade. Meanwhile, Thraustila stepped forward and killed Heraclius. Most of the soldiers standing close by had been faithful followers of Aëtius and none lifted a hand to save the emperor.
It is important to note that while J. B. Bury viewed Aëtius as a great military commander, and giant figure of history, he does not consider that the battle was particularly decisive. He argues that 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 on the next day, to preserve the balance of power. Then again, the Huns may have abandoned the siege of Orleans precisely because Aëtius's armies were advancing on them.
In Bury's view, the Battle of Nedao, three years later, was more important. The Germans rose up against the Huns after Attila's death, and defeated them at Nedao, in 454. This determined that there would be no Hunnic Empire, which Bury thinks would have been unlikely even if they had crushed the Germans that time. For Bury, the result of the battle of the Catalaunian Plains determined chiefly whether Attila spent his last year looting Gaul or Italy.
Bury's view remains in the minority, and the battle is considered crucial by virtually every other major historian. What is more, Bury does not challenge the majority view that Aëtius was a major historical figure, who single-handedly held up the dying Empire for three decades. As to Chalons, Gibbon states the majority view quite eloquently:
John Julius Norwich also strongly disagrees with Bury, as does William E. Watson, Sir Edward Creasy, and Poke, saying that "the entire fate of western civilization hung in the balance" in the campaigns of Attila, and that Chalons was a pivotal turning point in history. He also caustically referred to the assassination of Valentinian by his own guards as an act he brought on himself by his foolish execution of Aëtius, the "Empire's greatest commander. Certainly Aëtius' military legacy is defined by Chalons, even though he effectively ruled the western empire from 433-450, and attempted to stabilize the European borders under a deluge of barbarians, including foremost, Attila and the Huns.
Gibbon views Aëtius in a positive light, as do Norwich, Creasy, Ferrill, and Watson. In 1980, Robert F. Pennel wrote in Ancient Rome from the Earliest Times Down to 476AD:
Gibbon believes it was not indifference but rather preoccupation with the Huns and other barbarians that led Aëtius to neglect the navy. The subsequent loss of Africa came after Boniface invited the Vandals. Gibbon makes clear that Aëtius simply lacked the means to preserve the declining Western Empire in its entirety, while Norwich concludes that he guarded the Empire for three decades and that the after-effects of Aëtius's death lie at the feet of the Emperor who foolishly killed him. At a time when Romans did little or none of their own fighting, and no effective navy existed in the West, Aëtius had all he could do to preserve some vestige of order in continental Europe.
One could argue that later Emperors Majorian, Leo I and Anthemius saw the necessity of regaining the African provinces. Should Aëtius have concentrated his efforts on saving Africa, to the detriment of maintaining some vestige of Empire in Europe? Michael Grant in his History of Rome states flatly that Aëtius was powerless to stop the loss of Africa. Aëtius had begun to move against the Vandals when the forces he sent had to be recalled to fight Attila. Since Aëtius relied on barbarian federates, and as no other Roman General had the respect of those barbarian troops, his death left the Empire bereft of virtually any army in the west.
It is highly notable that Bury, whilst not believing the Battle of Chalons was significant, did believe in the significance of Aëtius's rule in general, saying "From the end of the regency to his own death, Aëtius was master of the Empire in the west, and it must be imputed to his policy and arms that Imperial rule did not break down in all the provinces by the middle of the fifth century."
In the end, there is some disagreement among historians as to the historical place of Aëtius. Was he the protector of Rome for three decades described by Gibbon, Norwich and Bury, the hero of Chalons described by Sir Edward Creasy, or should he be condemned for the loss of Africa, though most historians say he was powerless to stop that loss? Although Bury is cited as a critic of Aëtius, he was not, and said of Aëtius's death: "Who was now to save Italy from the Vandals?" The answer was no one. There was not one figure in the Empire able to take Aëtius's place as the champion and defender of the West. The certain thing about Aëtius's place in history is that he will forever be remembered as the last great Western Roman General, and the General who defeated the dreaded Attila the Hun.
Aëtius is played by Powers Boothe in the 2001 TV Miniseries Attila. Here he is portrayed as an anti-hero who accomplishes his goals through unorthodox methods. Aëtius is portrayed as the heroic 'Last of the Romans' in William Napier's Attila trilogy (2005), uniting the Romans and the Goths in one final, titanic battle to stop the Huns in their tracks, in the epochal Battle of the Catalaunian Fields.
While he does not appear in person, Aëtius' battle with Attila is documented in detail in Jack Whyte's book "The Eagle," during a conversation between King Arthur and Seur Clothar.
Aëtius, Galla Placidia and Stilicho all appear as central characters in Jose Gomez-Rivera's historical novel "Flavius Aëtius: The Last Conqueror," published in 2004.
Aëtius, Attila and Theodoric all appear in Michael Curtis Ford's fourth novel entitled "The Sword of Attila," published by Thomas Dunne Books in 2005.