The effect of the Donatist controversy on the economy and administration of the African provinces cannot be measured but was certainly profound. At the very moment of the effective victory of the African church, the rest of the Roman Empire was crumbling to ruin. In 406 the Rhine was crossed by Vandals, Alani, Suebi, and others who overran most of Gaul and Spain within the next few years. In 408 Alaric and the Visigoths invaded Italy and in 410 sacked Rome. Although the empire in the west survived for some time longer, the emperors were increasingly at the mercy of their barbarian generals. Meanwhile large tracts of imperial territory were lost as invading tribes settled them. Africa escaped for a while, though only death prevented Alaric from leading the Goths across the Mediterranean. Retaining Africa became ever more vital to the survival of what was left of imperial authority. In this situation the comites Africae were increasingly tempted to intrigue for their own advantage. One of them, Bonifacius, is said to have invited the Vandals, who at the time were occupying Andalusia, to his aid, but it is more likely that the Vandals were attracted to Africa by its wealth and needed no such formal excuse. Led by their king Gaiseric, the whole people, 80,000 in all, crossed into Africa in 429 and in the next year advanced with little opposition to Hippo Regius, which they took after a siege during which Augustine died. After defeating the imperial forces near Calama, they overran most of the country, though not all the fortified cities. An agreement made in 435 allotted Numidia and Mauretania Sitifensis to the Vandals, but in 439 Gaiseric took and pillaged Carthage and the rest of the province of Africa. A further treaty with the imperial government (442) established the Vandals in Africa Proconsularis, Byzacena, Tripolitania, and Numidia as far west as Cirta.

Although the Vandals were probably no more deliberately destructive than other Germanic invaders (the notion of “vandalism” stems from the 18th century), their establishment had strong adverse effects. The imperial authorities had to reduce the taxes of the Mauretanias by seven-eighths after they were devastated. Over much of northern Tunisia, landowners were expelled and their properties handed over to Vandals. Although the agricultural system remained based on the peasants, the expulsions had a serious effect on the towns with which the landowners had been connected. The Vandals, like other invading tribes except the Franks, were divided from their subjects by their Arianism. Although their persecution of Latin Christians was exaggerated by the latter, Vandal kings certainly exercised more pressure than others. This was no doubt in response to the vigour of African Christianity, which kept the loyalty even of those who had little to lose by the substitution of a Vandal for a Roman landlord.

Gaiseric was perhaps the most perceptive barbarian king of the 5th century in realizing the total weakness of the empire. He rejected the policy of formal alliance with it and from 455 used his large merchant fleet to dominate the western Mediterranean. Rome was sacked, the Balearic Islands, Corsica, Sardinia, and part of Sicily were occupied, and the coasts of Dalmatia and Greece were plundered. Although trade continued, Gaiseric’s actions accelerated the breakup of the economic unity of the western Mediterranean, which already was being threatened by the creation of the other barbarian kingdoms. Gaiseric’s successors were less formidable: Huneric (477–484) launched a general persecution of the Latin church, apparently from genuine religious fanaticism rather than for political reasons, but his successor adopted a milder policy. Later, under Thrasamund (496–523), there is evidence that many Vandals adopted Roman culture, but the tribe retained its identity until the Byzantine reconquest.

A significant development of the Vandal period was that independent kingdoms, largely of Libyan character, emerged in the mountainous and desert areas. They appeared first in the Mauretanias, where the Roman frontier, already drawn back under Diocletian, receded further under the Vandal kings. By the end of Vandal rule, independent kingdoms existed in the region of Altava (Oulad Mimoun), in the Ouarsenis Mountains, and in the Hodna region (in present-day Algeria). After 480, towns to the north of the Aurès Mountains, such as Thamugadi, Bagai, and Theveste, were sacked by the inhabitants of another kingdom in the Aurès. All the names of the known chieftains are Libyan in character, though the survival of Romanized elements within some of the kingdoms is attested by the fact that epitaphs in Latin continued, Roman names were still used, and a dating system based on the founding date of the Roman province of Mauretania was even maintained. Finally, as a harbinger of a serious threat to settled life, whether Roman or Libyan, tribes that had retained a nomadic way of life on the borders of Cyrenaica and Tripolitania and caused much damage in the 4th century began to push westward and were already a serious threat to the southern parts of Byzacena by the end of Vandal rule.

The Byzantine period

North Africa held an important place in the emperor Justinian’s scheme for reuniting the Roman Empire and destroying the Germanic kingdoms. His invasion of Africa was undertaken against the advice of his experts (an earlier attempt in 468 had failed disastrously), but his general Belisarius succeeded, partly through Vandal incompetence. He landed in 533 with only 16,000 men, and within a year the Vandal kingdom was destroyed. A new administrative structure was introduced, headed by a praetorian prefect with six subordinate governors for civil matters and a master of soldiers with four subordinate generals.

It required a dozen years, however, to pacify Africa, partly because of tribal resistance in Mauretania to an ordered government being reestablished and partly because support to the army in men and money was poor, leading to frequent mutinies. A remarkable program of fortifications—many of which survive—was rapidly built under Belisarius’s successor Solomon. Some were garrison forts in the frontier region, which again seems to have extended, at least for a while, south of the Aurès and then northward from Tubunae to Saldae. But many surviving towns in the interior were also equipped with substantial walls—e.g., Thugga and Vaga (Béja, Tunisia). There were further difficulties with the Mauretanian tribes (the Mauri) after Justinian died (565), but the most serious damage was done by the nomadic Louata from the Libyan Desert, who on several occasions penetrated far into Tunisia.

Africa shows a number of examples of the massive help given by Justinian in building—and particularly decorating—churches and in reestablishing Christian orthodoxy, though surviving Donatists were inevitably persecuted. Seriously weakened though it had been under the Vandals, the African church retained some traces of its vigour when it led the opposition of the Western churches to the theological policies of emperors at Constantinople—e.g., those of Justinian himself and also of Heraclius and Constans II immediately before the Arab invasions.

Little is known of the Byzantine period in the Maghrib after the death of Justinian. The power of the military element in the provinces grew, and in the late 6th century a new official, the exarch, was introduced whose powers were almost viceregal. Economic conditions declined because of the increasing insecurity and also the notorious corruption and extortion of the administration, though whether this was worse in Africa than in other parts of the Byzantine Empire is impossible to say. It is certain that the population of the towns was only a small proportion of what it had been in the 4th century. The court of Constantinople tended to neglect Africa because of the more immediate dangers on the eastern and Balkan frontiers. Only once in its latest phase was it the scene of an important historical event; in 610 Heraclius, son of the African exarch at the time, sailed from Carthage to Constantinople in a revolt against the unpopular emperor Phocas and succeeded him the same year. That Africa was still of some importance to the empire was shown in 619; the Persians had overrun much of the east, including Egypt, and only Africa appeared able to provide money and recruits. Heraclius even thought of leaving Constantinople for Carthage but was prevented by popular feeling in the capital.

In view of the lack of evidence for the Byzantine period, and the still greater obscurity surrounding the period of Arab raids and conquest (643–698) and its immediate aftermath, conclusions on the state of the Maghrib at the end of Byzantine rule are speculative. Much of it was in the hands of tribal groups, among which the level of Roman culture was in many cases no doubt negligible. Even before the Arab attacks began, the picture seems to be one of a continual ebb of Latin civilization and the Latin language from all of the Maghrib except along the coastal fringes of Tunisia, and the development and expansion of larger tribal groupings, some, though not all, of which were Christian. Also, the Byzantine administration was, in a sense, foreign to the Latin population. The military forces sent from Constantinople to stem the invasion were ultimately inadequate, though Arab conquest of the region could not be secure until Carthage was captured and destroyed and reinforcements by sea interdicted. The most determined resistance to the Arabs came from nomadic Libyan tribes living in the area around the Aurès Mountains. Destruction in the settled areas in the earlier attacks, which were little more than large-scale raiding expeditions, was certainly immense. It has been held that town life and even an ordered agricultural system almost disappeared at that time, though some scholars believe that a modicum of these survived until the invasions of larger nomadic groups, in particular the Banū Hilāl, in the 11th century. Latin was still in use for Christian epitaphs at El-Ngila in Tripolitania and even at Kairouan (Al-Qayrawān) in the 10th and 11th centuries. However, throughout the Maghrib the conversion of various population groups to Islam rapidly Arabized most of the region in language and culture, though the modalities of these profound changes remain obscure.

Belgian scholar Henri Pirenne formulated a theory, widely discussed, that the essential break between the ancient and medieval European worlds came when the unity of the Mediterranean was destroyed not by the Germanic but by the Arab invasions. The history of the Maghrib is an important element in this debate, for there one can see the complete replacement of a centuries-old political, social, religious, and cultural system by another within a short span of time.

Roman Cyrenaica

Much of the Roman period in Cyrenaica was peaceful. Some Roman immigrants resided there at an early date, and some of the Greeks received Roman citizenship. A famous inscription of 4 bc contains a number of edicts of the emperor Augustus regulating with great fairness the relationship between Roman and non-Roman. The character of its civilization, however, remained entirely Greek. Jews formed a considerable minority group in the province and had their own organizations at Berenice and Cyrene. They took no part in the great revolt of Judaea in ad 66 but in 115 began a formidable rebellion in Cyrene that spread to Egypt. No reason for it is known. It caused great destruction and loss of life, and Hadrian took special measures to reconstruct Cyrene and also sent out some colonists. Peaceful conditions returned, but in 268–269 the Marmaridae, inhabiting the coast between Cyrenaica and Egypt, caused trouble. When Diocletian reorganized the empire, Cyrenaica was separated from Crete and divided into two provinces: Libya Superior, or Pentapolis (capital Ptolemais), and Libya Inferior, or Sicca (capital Paraetonium [Marsā Maṭrūḥ, Egypt]). A regular force was stationed there for the first time under a dux Libyarum. At the end of the 4th century, the Austuriani, a nomad tribe that had earlier raided Tripolitania, caused much damage, and Cyrenaica began to suffer from the general decline of security throughout the empire, in this case from desert nomads. A notable phenomenon of the 5th and 6th centuries, as in Tripolitania, was the number of fortified farms, most frequent in the Akhḍar Mountains and south of Boreum (Bū Quraydah) and also apparently in the region of Banghāzī.

Christianity no doubt spread to Cyrenaica from Egypt. In the 3rd century the bishop of Ptolemais was metropolitan, but by the 4th century the powerful bishops of Alexandria consecrated the local bishops. The best-known Cyrenaican is Synesius, a citizen of Cyrene with philosophic tastes who was made bishop of Ptolemais in 410 partly because of his ability to obtain help for his province from the imperial authorities. Under Justinian a number of defensive works were constructed as elsewhere in Africa—e.g., Taucheira, Berenice, Antipyrgos (Tobruk), and Boreum. Recent excavations of a series of churches reveal the expenditure he devoted to their beautification, in what was a province of minor importance. On the eve of the Arab conquest (643), the general condition of Cyrenaica would appear to have been on a par with most of the other eastern provinces of the empire.