Ever since Edward Gibbon wrote his Decline and Fall of the Roman Empire the question why, when and indeed whether this great Roman Empire fell has been vigorously pursued by historians. It has been observed that at least 210 explanations have been offered, some frankly ridiculous (‘Semitization’, homosexuality, decline in manliness).1 The argument that it was the barbarian invasions that destroyed Rome – both the city and its empire – lost favour and has returned to favour.2 Some historians have insisted that the whole concept of the ‘fall of Rome’ is a misconception, and have emphasized the continuity of the Roman inheritance.3 Yet from a Mediterranean perspective, it is abundantly clear that the unity of the Great Sea had been shattered by 800. That leaves several centuries in which to place the process of disintegration, and several suspects: the Germanic barbarians in the fifth century and after, the Arab conquerors in the seventh century, Charlemagne and his Frankish armies in the eighth century, not to mention internal strife as Roman generals competed for power, either seeking regional dominions or the crown of the empire itself. Evidently there was no single ‘cause’ for the decline of Rome, and it was precisely the accumulation of dozens of problems that brought the old order to an end, rupturing the ‘Second Mediterranean’.
During the long period from 400 to 800, the Mediterranean split apart economically and also politically: the Roman emperors saw that the task of governing the Mediterranean lands and vast tracts of Europe west of the Rhine and south of the Danube exceeded the capacity of one man. Diocletian, ruling from 284 onwards, based himself in the east at Nikomedeia, and entrusted the government of the empire to a team of co-emperors, first another ‘Augustus’ in the west, and then, from 293 to 305, two deputies or ‘Caesars’ as well, a system known as the Tetrarchy.4 His residence in Nikomedeia was itself a prelude to the decision by Constantine to establish a ‘New Rome’ in 330; after looking at the site of Troy, the city from which the Roman people claimed its origins, he chose instead the emporium of Byzantion, with its fine harbour and its strategic position on the trade route linking the Black Sea to the Mediterranean. The other startling change that took place was, of course, Constantine’s official recognition of Christianity, after centuries during which it had existed as an underground religion.
Italy remained the base for western emperors until 476, when the last, aptly named Romulus, ‘the little emperor’ (Augustulus), was deposed by the Germanic warlord Odoacer. But the centre of power had shifted eastward; and this was only to recognize the economic realities of the Mediterranean: it was in the east that the trading world of the Hellenistic and Ptolemaic eras still flourished, with busy ports such as Alexandria, Gaza and Ephesos, united by trade links and by their common Greek culture. Although it would be simplistic to contrast a predominantly urban East with a predominantly rural West, for the eastern lands were still mainly populated by farmers and pastoralists, the concentration of towns along the shores of the eastern Mediterranean and the variety of agricultural pursuits in the East created a more complex economy. The rich textiles of late Roman Egypt can still be appreciated in museums; and luxury goods circulated in greater volume east of Sicily. The pattern of distribution of more basic goods also changed. One consequence of the foundation of Constantinople was that the grain of Egypt was now diverted from the Old Rome to the New.5 In 330 this appeared to be a harmless enough change. Africa in any case supplied two-thirds of Rome’s grain. It was a prosperous area, and Carthage was now the largest city in the Mediterranean after Rome and Alexandria. If, as is possible, the population of the empire was declining in the late third and fourth centuries, as a result of disease, the continuing strength of the North African provinces ensured that the western capital would still be fed. Roman and Carthaginian senators and equestrians enlarged their African estates.6 Hereditary guilds of shippers, or navicularii, were placed under imperial protection; members were entitled to tax reductions and were granted equestrian status. Although the imperial fisc did not intervene directly in the management of shipping, its patronage of the navicularii ensured that the traffic in grain remained lively. African farmers also valued olives and vines as sources of income; the region flourished as an exporter of oil and wine towards Italy and elsewhere. ‘African red-slip ware’ became the staple pottery not just of the Mediterranean but of areas deep inland in Gaul and as far away as Britain. Among goods that arrived in return were Italian bricks. It was not that the Africans were ignorant of brick-making; but bricks provided excellent ballast in grain ships as they returned to Africa empty of their wheat.7 It was a boom time in Africa, and especially for Carthage. The city was well laid out with a criss-cross pattern of streets, and it contained handsome buildings – the Carthaginians were especially fond of their amphitheatre and it was difficult to lure them from the games even when barbarian attackers threatened. Its glory was the port, for the circular port of old Carthage was restored and a handsome hexagonal outer harbour was also built under Trajan. It was a twin of the hexagonal port he built at Portus near Ostia and the outline of the ‘Punic Ports’ can still be traced.8
Africa was also a peaceful place. From the third century onwards the outer frontiers of the empire had been under assault by barbarians; in far-off Britain the ‘counts of the Saxon shore’ organized the defence against Germanic raiders from across the North Sea. Even when hordes of Goths, Suevi and other Germanic peoples marched through Gaul, Italy and Spain in the years around 400, and even after Rome itself was sacked in 410, Africa seemed to be safe.9 One African intellectual, Augustine, who became bishop of Hippo and died in 430, was, admittedly, so shocked by the sack of Rome that he was inspired to write his masterpiece, The City of God, in which a heavenly ‘city’ was shown to surpass the fragile earthly city and empire of Rome. Yet Hippo and Carthage, at least, seemed to be protected by the sea. The barbarians were known to be soldiers, not sailors. The Goths were bottled up in Italy and could not even cross from Calabria to Sicily. Other barbarians, the Vandals and Alans, were heading westwards, into the mountains of Spain. It was hard to see what threat they could pose.
The Vandals were Germanic and for a time inhabited areas that now form part of southern Poland; they were adherents of Arian Christianity, like most barbarian peoples, following a creed that argued that the Son was not co-equal and co-eternal with the Father but proceeded from the Father. Although it has become a byword for destruction, the term ‘vandalism’ was first coined only in 1794, by a French bishop in despair at the destruction wreaked by the revolutionaries.10 The Vandals certainly enjoyed piling up treasure, and the Vandal kings were reluctant to release their accumulated gold and silver back into the economy – the process known to economic historians as thésaurisation. The Alans, by contrast, originated in the Caucasus and had migrated into south-eastern Europe; their language was Iranian, and their customs differed significantly from those of the Vandals – for instance, they did not keep slaves. These unlikely allies entered Spain and carved it up among themselves, but in 416 they were attacked and massacred by the Gothic warlord Wallia in the name of a newly forged, and very temporary, Gothic–Roman alliance. Barbarians were often better at fighting one another than at fighting the Romans. The Vandals in Baetica, roughly modern Andalucía, are said to have been virtually wiped out. But, after so momentous a defeat, the survivors needed to seek other lands. Their aim was to conquer and settle, not to plunder and vanish. The choice they made, Africa, may seem logical enough, since it lay so close by. In the summer of 429, led by their lame but ruthless king, Geiseric, they made their way to the Straits of Gibraltar.
The region around Tangier, Tingitania, was governed from Spain and was the one Roman base in an area that was otherwise controlled by Mauretanian kings, whose relationship with Rome had been, in general, cautiously polite. Rome saw less value in this region than in other parts of North Africa and was satisfied with loose alliances.11 Geiseric, too, was more interested in gaining control of the wealthiest parts of Africa. Carthage lay in a promised land full of wheat and olive trees, conveying an even more opulent impression than southern Spain.12 Yet he had to move as many as 180,000 soldiers, women and children across the Straits (a figure that suggests the story of near-annihilation in Baetica was greatly exaggerated).13 But he had no ships, and many of the boats plying these waters would have been capable of carrying seventy people at best. If he did manage to gather together a few hundred smallish vessels, he could have ferried his people across the Straits in about a month. That still leaves the question of where he found all these boats. His route took him across the Straits of Gibraltar on the Atlantic side, from Tarifa, the southernmost point in Spain, to the beaches between Tangier and Ceuta. That short journey, repeated time after time in what are, even in summer, often inhospitable waters, brought the Vandals and Alans into Tingitania, but they did not linger, and marched eastwards overland, taking up to three months to reach Hippo in May or June 430.14 Hippo resisted for fourteen months, for the Vandals were not greatly experienced at siege warfare and Hippo was well defended by its Roman walls – a good example of foresight, for during the long years of pax romana city defences could easily have been neglected. Among those looking out from the city was its bishop, Augustine, who passed away during the siege. He could reflect that the destruction that had been brought by the heretic barbarians to Rome now threatened his own province.
The conquest of Hippo was followed by the establishment of a new Arian order in which nearly 500 Catholic bishops were expelled from their often tiny sees for adhering to the teachings of the Council of Nicaea. This marked a departure from the Arian practice of tolerating Catholics.15 The conquest of Carthage eventually followed, but Geiseric was very patient; the city fell in 439, though by then the lands around it were already in Vandal hands. It became the new capital of the kingdom. However, the Vandals in Africa were not destroyers; they owed much to the old order. Geiseric realized that he had to be more than king over his people – rex Vandalorum et Alanorum, ‘king of the Vandals and the Alans’, as his official title ran.16 In 442, the Vandals entered into a treaty with the Romans, under the terms of which the king exercised full territorial sovereignty.17 There is no evidence that Vandal rule led to economic decline, even if much of the gold Geiseric accumulated stayed in his treasury. Building programmes continued; oriental merchants arrived in Carthage, bringing Byzantine coins; North African merchants travelled to the East; the handsome commercial harbour of Carthage was renovated.18 There was a significant increase in the number of eastern Mediterranean amphorae imported into Carthage during the Vandal period. The Carthaginians also dined off the best pieces of local red-slip ware. The fact that North African grain was no longer requisitioned for export to Rome, but was handled by local merchants, stimulated economic enterprise.19 The Vandals were fond of eastern silks, of bath-houses, banquets and theatres; they enjoyed punting. They acted as patrons of Latin poetry, and were as Romanized as the Goths who, settling in Italy, began the beautification of their centre of government at Ravenna.20 Like the Goths, though, they kept their Germanic names (Gunthamund, Thrasamund, and so on) from generation to generation, though Latin and, to a lesser extent, Punic functioned as the lingua franca in Africa. Rural life was not interrupted by the conquest, as is shown in remarkable wooden estate records from the hinterland of the Vandal kingdom, the so-called Albertini tablets.21 The old system did not just linger; it was full of its traditional energy. The Roman, Punic and Moorish population of north-west Africa provided the Vandals with the shipping that was needed to sustain the Vandal state.22 Ships were used for trade or troop movements as circumstances demanded. In 533 King Gelimer possessed 120 vessels which he sent to Sardinia in the hope of defeating the island’s rebellious governor. The Vandals did not require traditional warships; when they crossed the sea to conquer other lands, they simply needed to be transported with their horses and arms.23
The Vandal kingdom was much more than the African provinces of the Roman Empire. Even before the invasion of Africa, the Vandals had despatched raids to the Balearic Isles; in 455, they annexed them.24 New opportunities opened up, following the death of the highly successful Roman general Aetius in 454 and the assassination of the distinctly less able western Roman emperor Valentinian III the year after.25 Their most daring expedition took the Vandal army to Rome in June 455. The aim was not an Arian holy war against the Catholics, but plunder: the Vandals were under instructions not to destroy and kill, but to find treasure, especially imperial treasure. They carried off a vast booty, including very many slaves (whom they treated with no consideration, splitting apart husbands and wives, parents and children). According to some accounts the treasure included the great candlestick and other golden vessels seized by Titus from the Temple in Jerusalem, which were kept in Carthage as trophies until the Byzantines recovered the city in 534.26 Geiseric also seized Corsica in 455 or 456, and used it as a source of wood for his ships – exiled Catholic bishops found themselves forced to work as woodcutters on the island. In the same period the Vandals attempted to conquer Sardinia, though it was lost around 468 and recovered by them only around 482. They settled the island with Moors deported from their African territory, the so-called Barbarikinoi, who gave their name to the wild mountains of Barbagia in north-eastern Sardinia. They were not shy of attempting to conquer Sicily as well, ruthlessly scouring the Sicilian Straits as early as 440, and again in 461 or 462, raiding the island each year after that. They managed to prise control of Sicily from the Romans for a time, but a little before the death of Geiseric (in 477, after half a century of war-mongering) they came to an agreement with the Germanic general Odoacer, who had deposed the last western emperor only a few months earlier, and now ruled as king of Italy. Odoacer paid tribute for Sicily but left only the western tip around Marsala under direct Vandal control. Still, it seemed for a time as if the Vandals would control the three granaries of the western Mediterranean: Africa, Sicily and Sardinia.27 Then, after deciding they had extracted as much from Sicily and Italy as they could hope to do, they began to raid the coasts of Greece and Dalmatia as well, devastating Zakynthos, in the Ionian isles, in the last years of Geiseric’s reign.
The Vandals had created a maritime empire of a very distinctive character. There is no evidence that they encouraged piracy on the high seas, nor that the kings took a direct interest in trade. They knew that they had placed their hands on the jugular vein of Rome when they gained control of the empire’s granaries, and famines recorded in Italy, around 450, may have been accentuated or even caused by Vandal interference in the grain traffic. They did not often engage with the fleets of the Roman Empire, for that type of naval warfare was now rare (although in the 460s Geiseric did manage to destroy two Byzantine fleets). While the high point of the Vandal empire was the reign of its founder, Geiseric, the Vandals were still a significant force in the sixty years that followed his death in 477. By 500, Arian Ostrogoths (‘eastern Goths’) ruled Italy, Arian Vandals ruled Africa, Arian Visigoths (‘western Goths’) ruled Spain and southern Gaul. The political, ethnic and religious geography of the Mediterranean had changed decisively in the century and a half since the foundation of the New Rome. The process of dis-integration was under way.
This disintegration has to be understood several ways. There was a gradual detachment of the western Mediterranean from the eastern Mediterranean; and there was a series of crises in both, from which the eastern areas suffered badly but recovered more quickly and decisively than did the West. The era of the invasions also had dramatic effects on the early Byzantine state, but in the West the result was the disappearance of imperial authority, whereas in the East imperial authority survived massive incursions by Goths, Slavs, Persians and Arabs that even brought invaders to the impregnable walls of seventh-century Constantinople. Much of Greece was under the rule of Slav tribes in the seventh century. Yet the economy of the entire Mediterranean was also under assault from a very different attacker. The 540s saw the arrival of plague, possibly bubonic and pneumonic plague pathologically similar to the Black Death of the fourteenth century.28 Like the Black Death, the plague of the era of Justinian carried away massive numbers of people, maybe 30 per cent of the population of Byzantium, particularly town-dwellers. Cold but dry winters in the eastern Mediterranean led to drought and famine, and possibly similar climatic changes much further east released plague from the lands in East Asia where it was residually endemic and allowed it to spread westwards.29 In addition, a cool phase during the late Roman Empire may have resulted in deterioration of the soil, while the abandonment of terraces created for the cultivation of vines and olive trees would have led to landslips and erosion. But there is a chicken-and-egg problem here: the abandonment of vines and olives implies a decline in demand, and something must have caused that. Another view is that over-exploitation of the soil by a swollen population living on the edge of the Mediterranean, demanding more and more cereals, denuded the soil of trees and other cover, with the result that topsoil was carried away into river mouths, which silted up. A series of ecological accidents (for the people of the time were unable to appreciate the effects of their actions) thus damaged the soils from which they lived, and resulted in famines and droughts. One would then expect the population decline around the Mediterranean to have begun before the arrival of the plague, which hit the weakened population all the harder because of the lack of resilience to disease following food shortages and local epidemics of less virulent diseases.30 All this may appear rather theoretical, but there is enough evidence, from North Africa, Ephesos in Asia Minor, Olympia in Greece, Nora in Sardinia and Luni in north-western Italy, to show that silting-up did occur.31
Under the Byzantine emperor Justinian I (527–65) vigorous efforts were made, notwithstanding the spread of disease, to re-establish Roman rule throughout the Mediterranean. Before the plague struck, Justinian had already recovered control of Carthage (534); money was then lavished on the city: a new portico was constructed in its famous circular harbour, and new walls and moats were set in place, for events a century earlier had shown that even a city in North Africa was vulnerable to land attack. The collapse of the Vandal kingdom was followed by Gothic Wars in Italy, led by Justinian’s brilliant general Belisarios; Byzantine armies swept into Sicily, and a mere two years after the fall of Carthage they captured Naples by a classic ruse, entering through a tunnel. Justinian saw the recovery of Italy as a matter of special prestige; Ravenna, previously the base of the Ostrogothic kings, became once again the seat of imperial officials, the exarchs, and its outport at Classis resumed its role as the base for the Byzantine navy. The harbour of Naples was fortified, since the Gothic enemies of Justinian remained on the rampage after Belisarios had won the city back for the emperor.32 The long arm of Byzantium even extended to the coastline around Genoa – the first signs of economic activity in an area that was to become one of the great centres of medieval Mediterranean trade.33 Not afraid to fight on several fronts at once, Justinian also despatched armies to southern Spain, gaining control of the region around Cartagena in the teeth of Visigothic opposition. With Sardinia and the Balearic islands also under Byzantine rule, a chain of communication was created stretching from the heartlands of Byzantium towards Ceuta and the Straits of Gibraltar.
Justinian’s attempt to re-establish a pan-Mediterranean Roman Empire stretched the resources of Constantinople at a time of economic crisis. Italy was severely damaged by war and disease.34 Optimistic attempts to improve harbours and to bolster the defences of port cities continued despite the demographic collapse following the plague. In the hope of reinforcing the link between Constantinople and Italy, the city of Dyrrhachion (the old Epidamnos) was surrounded by an impressive series of walls and towers, parts of which still survive. Dyrrhachion stood at the end of the overland route to Constantinople, the Via Egnatia, but access to the Aegean by sea was also facilitated by similar works at Corinth, even though much of the population, already severely depleted by plague, decamped to the Aegean island of Aigina.35 A similarly mixed story can be told of Carthage. The harbour works did not guarantee the city’s economic vitality. The number of eastern amphorae dipped significantly following the Byzantine recovery of Carthage. Paradoxically, just as political control was imposed from the East, commercial links to the East weakened; the decline in trade may have been the result of renewed attempts to bring the grain trade under state control.36
The sixth century was also a time of very varied fortunes in the eastern Mediterranean; Ephesos experienced dramatic decline, as did Athens and Delphi, though Alexandria remained a lively city of about 100,000 inhabitants until the middle of the century. In some areas, however, there was new vitality: the city of Gortyna in Crete was adorned with handsome new buildings in the seventh century, following an earthquake, and became the centre of a successful pottery industry. One advantage Crete, and also Cyprus, had was that the Slav invasions did not reach these islands. Hoards of early seventh-century gold coins attest to their continuing prosperity. Several Aegean islands such as Samos and Chios acted as hosts to refugees from the Slavs, and were invigorated by the arrival of new settlers at a time of population decline elsewhere.37 The ‘Rhodian Sea Law’ emerged as the standard code of maritime law in and beyond Byzantium.38 As well as northern barbarians, Byzantium faced the sophisticated menace of the old rivals of the Greek world, the Persian emperors. Their invasions had a devastating effect on the cities of the Mediterranean coastline. Sardis was an imposing regional capital until 616, with marble-paved streets, porticoes and one of the largest synagogues in the Mediterranean; the city’s destruction by the Persians left a pile of burned-out ruins, and it was never reconstructed. Pergamon, once famous for its library, shared a similar fate.39
Despite these calamities, some of the old trading networks remained alive, and were even reinvigorated. Po valley grain was exported from Classis when Byzantine rule resumed there. Naples, on the other hand, loosened its ties with Africa, which had once supplied it with large amounts of grain. This can be measured from the decline in the once plentiful African pottery found in sixth-century archaeological levels in Naples.40 The decline of African red-slip ware contrasts with the arrival in Naples of noticeable quantities of pottery from the eastern Mediterranean, including amphorae from Samos, one of the islands that had flourished while mainland Greece suffered catastrophic collapse under Slav rule.41 In fact, around 600 Samian pottery appeared in Rome, Ravenna, Syracuse and Carthage, so the links between the eastern Mediterranean and the newly recovered lands in Italy and Africa were evidently maintained and possibly even strengthened. Southern Italy and Sicily retained ties to the outside world and the Lombard rulers of southern Italy were able to mint gold coins. The Adriatic was an outlying Byzantine lake, and it is in this period that the first stirrings of a group of muddy ports at its very top can be detected, the communities out of which Venice would emerge. Conditions were more difficult further west. Luni declined steeply and never recovered. Around 600 the inhabitants could only mint coins made of lead.42 There were some ties between Genoa and Byzantium, but they are likely to have been more political than commercial. Marseilles retained a lead among the trading centres of the western Mediterranean, but was a pale shadow of the great Greek city of the past. The number of eastern amphorae shrank in the sixth century, so that by 600 it was only a quarter of the number around 500; in the seventh century these amphorae vanished. On the other hand, African amphorae staged a recovery in the sixth century, so medium-distance trade within the western Mediterranean continued through Marseilles. Nor were contacts with the East totally severed. Bishop Gregory of Tours, chronicler of the hideously brutal Merovingian kings of Gaul, mentioned wine from the Syro-Palestinian ports of Gaza and Laodicea.43 Striking confirmation of this statement has been obtained from the wreck of a ship dating to Gregory’s time, found near Port Cros off southern France. It carried wine amphorae from the Aegean and Gaza.44
About eighty shipwrecks from this period have been identified. Around 600 a vessel sank off the southern French coast carrying pitch, North African pottery, Gazan amphorae and pitchers with graffiti in Greek letters; the ship was poorly constructed, with thin planking and ill-fitting joints, so it is no surprise that it sank. The boat was not large; it displaced less than 50 tons and could carry at most 8,000 modii of wheat, a fraction of the capacity of Roman grain ships.45 Sixth- and seventh-century ships were smaller than their Roman predecessors. A wreck found off Turkey, at Yassı Ada, from about 626, was built using lighter nails than the Romans would have employed; displacing over 50 tons, it was a cheaply built vessel, ‘lasting just long enough to turn a good profit’.46 On the other hand, it possessed a well-stocked galley with a tile roof, whose contents – bowls, plates and cups – suggest that it came from the Aegean or Constantinople.47 Occasionally ships with more costly cargoes went down: the Marzameni wreck, from Sicily, dates from around 540 and carried up to 300 tons of green and white marble. The vessel was carrying the interior furnishings of an entire church, similar to those of churches in Ravenna and Libya. These fine pieces were sent across the sea as an advertisement for religious uniformity: one style of church design would reflect one theology under one emperor, Justinian the Great.48 The eastern Mediterranean shipwrecks suggest more intensive contacts, linking the islands and the coasts. A ship wrecked off the south-west Turkish coast, at Iskandil Burnu, and dating from the late sixth century, was carrying wine from Gaza and what has been identified as a kosher casserole pot, so it is quite possible that the vessel was owned by a Jew (as in the story of Amarantus, the Jewish captain at the start of the fifth century).49
The balance sheet for Byzantium combines evidence for a serious economic depression with evidence for continued vitality, most marked in the eastern Mediterranean islands. This is only to be expected after the demographic earthquake of bubonic plague. The commercial map of the Mediterranean was recast, as old centres faded and new ones gained in vitality. Surviving nodes of economic vitality seeded the Byzantine Mediterranean, making possible the revival of the eighth and ninth centuries. Further west, recovery was much slower and more difficult.