The western empire was still able to achieve occasional victories over the barbarians in the early fifth century. One such victory was the battle of Pollenzo near Asti in 402 when the general Stilicho defeated the Goths.

In the late fourth century there was little sign of imminent upheaval in the Mediterranean heartlands of the Roman Empire. The disorders of the third century had been overcome by soldier-emperors whose reforms had safeguarded the frontiers and created political stability. Following the conversion of Constantine Christianity had established a firm hold and lavish programmes of artistic and architectural patronage testified to the wealth and self-confidence of a revivified empire.

After the death of the Emperor Theodosius I in 395, however, divisions between the Latin and Greek halves of the empire became more evident. The east far outshone the west in intellectual achievement, prosperity, and the number and size of its cities; whereas Gaul and Britain could muster 114 civitates, more than 900 cities constituted the thriving centres of political and economic life in the east. Not only the resources but the ideological backing for imperial authority were stronger in the east, where the Hellenistic heritage reinforced acceptance of the imperial cult and the trappings of autocratic power. Papyri from Egypt and excavations of Syrian villages suggest a level of agricultural prosperity in sharp contrast with the slave-run latifundia of Italy or the peasant hovels of Gaul. Eastern society was relatively meritocratic, with officials drawn from loyal, capable members of local urban elites, whereas in the west even the ‘new men’ appointed by fourth-century emperors rapidly adopted the powers, traditions, and arrogance of the senatorial aristocracy. In the east the propaganda of scholar-bishops and the proselytizing of ‘holy men reinforced allegiance to the ideal of a God-given Christian empire, while in the west Christianity was less firmly established and undermined attachment to the empire by offering an alternative to imperial service. In Constantinople the east possessed a cosmopolitan and strategically sited capital which came to surpass Rome and the other imperial residences of the west in size and splendour.

The most immediate problem in 395 was renewed barbarian inroads. In 376 a horde of Germans, mostly Visigoths, had crossed the Danube frontier in search of refuge from the Huns, a fearsome tribe of steppe nomads. Tensions between the incomers and their Roman hosts led to a battle at Adrianople in 378, in which a Roman army was annihilated and the Emperor Valens killed. The immediate threat was contained, but the Goths were permitted to settle on Roman territory. Under their king, Alaric, they launched devastating raids into Greece, before moving north into modern Yugoslavia. In 401 Alaric invaded Italy and for ten years the peninsula remained at the mercy of Gothic plundering and extortion. The Romans lacked reliable forces to defeat the invaders, and the funds necessary to buy Alaric off. In exasperation at not receiving the money and land which he demanded, Alaric besieged and sacked Rome in 410. The destruction caused was limited but the psychological blow to Roman morale of the first sack of Rome since the Gaulish attack of 390 BC was immense. St Jerome wept on hearing the news in his cell in Bethlehem and a bitter polemic exploded between Christians and pagans. Christian views of society and history were worked out in such influential works as Augustine’s City of God in order to counter pagan attacks.

Italy was spared long-term effects from the rampaging of the Visigoths, since they withdrew to Gaul after Alaric’s death in 410. More lasting and disruptive were the effects of imperial weakness in Gaul, where a force of Vandals, Sueves, and Alans broke through the Rhine frontier in the winter of 406/7 and Constantius, a usurper from Britain, set up a short-lived empire based on ArIes. By 418 the imperial government got the upper hand over the twin dangers of sedition and invasion by the increasingly familiar expedient of setting a thief to catch thieves. The promise of land and subsidies together with the threat of a food blockade enforced by Roman naval power induced the Visigoths into repelling the Alans and Vandals and settling in Aquitaine as Roman federati (allies).

The first half of the fifth century saw the settlement of Germanic peoples in most areas of the western Mediterranean, and in the main this process took place smoothly and peacefully. In Gaul the Visigoths and the Burgundians, who were settled first on the Rhine and later in Savoy, served as a bulwark against peasant rebels and other barbarians, took only a proportion of the land for themselves, and allowed the Romans to retain their institutions as ,nominal subjects of the emperor. Spain lapsed into a period of confusion and obscurity following the invasion of the Vandals and their Sueve and Alan allies. In 429 the Vandals moved on to Africa and Visigothic overlordship was eventually established over most of the country. Africa is the province of the western Mediterranean whose fate approximates most closely to the popular view of catastrophic invasion. The Vandals, led by their remarkable king, Gaiseric, were quick to throw off the facade of allied status and seized Carthage and the other cities of what was once one of the richest of Rome’s provinces. The Roman population was relentlessly taxed, the Catholic hierarchy was persecuted, and naval raids were launched against Roman targets throughout the Mediterranean.

Italy and the imperial court at Ravenna felt little direct effect from what appeared to be a phoney war against the barbarians. This immunity was the achievement of two capable commanders-in-chief, Constantius and Aetius, ‘the last of the Romans’, who manipulated the invaders in order to shore up the tottering empire. Aetius’ balancing act failed when his Hun allies turned against him and invaded northern Italy. The empire became the plaything of autocratic factions and in 476 the boy-emperor, Romulus, ironically nicknamed Augustulus (‘the little emperor’) was deposed by Odoacer, the commander of the German mercenaries in Italy, who sought land for his troops and direct rule of Italy for himself.

A graphic account survives of the running down of Roman public life in Noricum (western Austria) in the face of German pressure. Once Roman supplies and payments were cut off, the demoralization of a population accustomed to Roman protection could only be staunched by the leadership of a charismatic holy man, and after his death the province had to be evacuated. In Italy, however, a complex civilian society remained intact, and the senatorial aristocracy maintained its privileged position, including its vast landholdings, its monopoly of lucrative governorships, and the cultivated literary life of its salons.

In Gaul the withering away of the empire left the senators as the main symbol of Roman legitimacy while relieving them of the burdens of imperial rule. Gradually, however, they found their political and social position marginalized as their offices and titles became redundant and their Germanic guests began to flex their muscles. The Visigoths set up a kingdom based on Toulouse, while the Burgundians in south-eastern Gaul established a sub-Roman state with twin capitals at Lyons and Geneva. The difficulties faced by senators in adjusting to new realities are displayed in the letters and poems of the scholar-aristocrat Sidonius Apollinaris. His attitude to the Germans ranged from admiration of a cultivated Visigothic king who played backgammon to exasperation at the ‘gluttonous’ barbarians billeted on his estate, ‘who spread rancid butter on their hair’. His evolution from literary escapism in the seclusion of his estates to conscientious activity as bishop of Clermont reflects a widespread process of clericalization; episcopal election became the means for a disorientated aristocracy to maintain its traditional leadership of the community and for preservation of Roman customs and culture.

With time the passive antagonism of the Roman population undermined the power of the Visigothic kings, despite their frantic attempts to court support by issuing Roman law codes, and facilitated their defeat at the hands of the newly converted king of the Franks, Clovis, at Vouille near Tours in 507. Thenceforth the Visigothic kingdom was confined to Spain apart from a small salient north of the Pyrenees in Septimania. The smoothness of the Visigoths’ withdrawal into Spain was made possible by the intervention of the Ostrogothic king, Theoderic, who became the most powerful barbarian monarch in the western Mediterranean after seizing Italy from Odoacer in 493. He is also the most interesting, since he combined capable war-leadership and an appreciation of the need to retain the identity of his people with a calculated admiration for the benefits of Roman civilization derived from his own experience of Constantinople as a hostage.

This ‘dual’ approach provided for lavish patronage of public works, the promotion of economic activity and the safeguarding of Roman customs, especially those of the Senate, whose support he cultivated to reinforce the legitimacy of his rule. His own people were kept segregated in settlements in north and central Italy under their own commanders, while the central and local administration was entrusted to Roman collaborators such as Cassiodorus, a senator from a parvenu Calabrian family. However, Theoderic’s position as the leader of a small heterodox people was always vulnerable, and towards the end of his reign uncharacteristically severe measures taken against the Roman population can be attributed to fears concerning the succession and the diplomatic noose which the Byzantines were tightening around his kingdom. Reconciliation between the Roman Church and the aggressively orthodox emperors of the east, combined with the nostalgic yearning of conservative senators for Roman rule, gave rise to suspicions of treasonable negotiations with Constantinople, which in turn led to the notorious episode of the arrest and execution of the philosopher Boethius.

For much of the fifth century the eastern empire had seemed destined to fall into a decline similar to that of the west. Its last representatives of the Theodosian house were equally incapable, its Balkan provinces were ravaged by Hun and Ostrogoth invasions and Constantinople itself was at times threatened. The eastern provinces of Syria and Egypt were racked by religious dissension over the nature of Christ, a matter of spiritual life and death to Christians preoccupied with salvation and with achieving a doctrinal orthodoxy that was pleasing to God. Gradually, however, the east’s underlying advantages enabled it to emerge . from its difficulties as a resilient and cohesive society. The impression that emerges is one of consensus around the ideal of a God-appointed Christian empire, prosperity reflected in lavish building throughout Asia Minor and the dynamic capital of Constantinople, and political stability enshrined in the rise of a new breed of trained, dedicated bureaucrats. One of the latter, an official named Anastasius, became emperor, and further strengthened the empire by cautious and tolerant policies of reducing taxes and trimming expenses. The full benefits of this political and financial stability were reaped by his successors, Justin I and his nephew Justinian.

Justinian, the most remarkable of Byzantium’s emperors, was denounced by a vituperative contemporary for ‘ruining the Roman Empire’ and ‘bringing everything into confusion’. In fact his efforts to turn the clock back to the great days of the universal Roman Empire had astonishing initial success. A small expedition was launched against the Vandal kingdom of North Africa, the longest standing thorn in Constantinople’s flesh, under the brilliant general Belisarius, and the people who had terrorized the Mediterranean in the fifth century were rapidly conquered. In the view of the historian Procopius the Vandals had become ‘of all nations the most lecherous’, and their military prowess had been sapped by their wealth. The emperor’s whirlwind success was celebrated in the extravagant prologues attached to the massive Code of Roman Law which he issued in 534. Justinian’s legislative activity, like his stalwart defence of religious orthodoxy, was based on an elevated view of the universal empire, which he saw as the terrestrial image of God’s heavenly kingdom. His autocratic leanings were reinforced by a savage uprising against his reliance on unpopular ministers in 532 and encouraged by his redoubtable empress, the former actress Theodora.

Throughout the 530s Justinian undertook a lavish programme of building, including the Church of Hagia Sofia in Constantinople with its dome of unprecedented size. His military success continued with an invasion of Sicily and Italy, and by 540 the Ostrogoths had lost their main political centres of Rome and Ravenna. Although his propaganda stressed the renewal of Rome’s greatness, his actions resulted in the replacement of the cosy bureaucratic’ system of the east by a ‘Stalinist’ regime based on his own megalomaniac energy, ruthless political and fiscal oppression of his subjects, reliance on unpopular toadies, and rigorous enforcement of doctrinal orthodoxy.

In the 540s Justinian’s luck ran out. Persia launched a devastating invasion of the east, the Slavs infiltrated the Balkans, and under an able new king, Totila, the Ostrogoths reduced the imperial foothold in Italy to a few coastal outposts. In 542 bubonic plague decimated the empire’s population, with catastrophic effects on urban and economic life, and in 548 his helpmate Theodora died. The remaining years of Justinian’s reign have a relentless, austere quality. In spite of all the vicissitudes the emperor kept his nerve, repelling invasions, sending a force to Italy under Narses which dealt the Ostrogoths the coup de grace in 553, and tirelessly seeking to reconcile his heretical subjects in the east to orthodoxy.

By his death in 565 Justinian appeared to have succeeded in restoring the glories of Rome. The Arian kingdoms of Africa and Italy had been returned to imperial rule, and even the Burgundian kingdom was taken over by Justinian’s Frankish allies in the 530s. Only Visigothic Spain held out, and it was threatened by internal dissensions and a Byzantine salient around Cartagena. In other ways Justinian’s reign marked a new beginning for the Roman Empire. His ideals of autocracy and Romano-Christian universalism became a programme to which all later Byzantine emperors subscribed. The upheavals of the fifth century had not destroyed the relatively uniform Roman life of the Mediterranean.