Aetius’ designation as ‘the last of the Romans’ is perhaps an appropriate description as, during the twenty years of his dominance, the empire had disintegrated still further. Its survival was now dependent on a variety of volatile peoples none of whom had any interest in remaining a loyal ally, especially when their leaders had the chance to extend their own territories. The Roman administration was kept afloat by hurried and usually ineffective diplomatic deals. Italy had become especially vulnerable to attack from the sea. The new emperor, Petronius Maximus, tried to consolidate his position by marrying his son to Valentinian’s daughter Eudocia. Gaiseric had been promised Eudocia for his own son back in 442 and so now had a fine excuse to send a fleet to Rome in 455 and sack it once again. In 458 he took Sicily, held as a Roman province for nearly 700 years.
The effectiveness of their navy had established the Vandals as the main threat to the empire. The new magister militum, Avitus, a Gallic aristocrat, determined to use the Visigoths to invade Africa. In the event the Visigoths exploited their indispensability to move into Spain, where the structure of Roman administration had by now collapsed. Britain, Spain, Africa, and much of Gaul had now fallen out of Roman control.
After the death of Petronius Maximus in 455 Avitus declared himself emperor but his continuing failure to tackle the Vandals and his Gallic origin meant he had little support among the senators of Rome, to whom the Vandal threat was the main concern. When a German commander of half Visigothic and half Suevic origin, one Ricimer, defeated the Vandals in a sea battle, the senators were impressed enough to choose him as the empire’s new strong man. An emperor, Marjorian, a former army officer, was also provided and the two combined to depose Avitus.
Between 456 and 472 it was Ricimer who managed what remained of the western empire. Emperors survived only with his support and were deposed or murdered when they lost it. Marjorian was executed in 461, probably as a result of attempts to make peace with the Vandals. His replacement, Severus, died, possibly poisoned by Ricimer, in 465. In 467 Ricimer saw the advantage of making an alliance with the east, accepting an eastern nominee, Anthemius, as emperor in the west in return for effective help against the Vandals. However, an expedition launched by the east against the Vandals in 468 proved a disastrous failure and relationships between Ricimer and Anthemius broke down so completely that Anthemius ended up as another of Ricimer’s victims, dragged from a church in Rome where he had sought sanctuary, and executed. When Ricimer himself died in 472 the empire outside Italy was effectively lost for good.
The eastern emperor, Zeno, now tried to impose his own nominee as emperor, one Julius Nepos, but he was expelled to Dalmatia where he had been previously the magister militum. His successor, his own magister militum, Orestes, appointed his son, Romulus Augustulus, as emperor and it was he who was deposed by Odoacer in 476.
The story of the last years of the empire of the west is one in which Roman administration gradually disintegrated. In many areas, as has been seen, the administration was simply delegated to German tribes, in others it atrophied. In the life of Severinus by Eugippius there is an atmospheric account of the last days of imperial rule in the province of Noricum. As late as the 470s there were still army units stationed in the main cities of the province. At one point their pay failed to arrive. One unit sent off a delegation to Italy to collect the money but no more was heard of it and the unit disbanded itself. Others followed and the defence of the frontier was, in effect, abandoned. Germans soon moved over the frontier to take control.