The Roman empire at the end of the fourth century had an enormously long frontier, stretching in the north-west from the Tyne-Solway line followed by Hadrian’s Wall in Britain,
Map 2.1 The Roman empire c. 400 CE.
Along the length of the Rhine and Danube rivers to the Black Sea, and in the east from the eastern littoral of the Black Sea near modern Batumi down through the Caucasus into Armenia, across the upper reaches of the Tigris and Euphrates rivers, through the great Syrian desert down to Sinai and across to Egypt, whence it followed the desert fringe across Libya/ Tripolitania into modern Tunisia and further west, north of the Atlas mountains, as far as the Atlantic Ocean. Defending such a vast territory was always a formidable task, and with relatively limited resources - an army of perhaps 250,000, including auxiliaries and allied forces, to defend a perimeter over 8,000 miles in length, as well as maintain internal security, combat brigandage and banditry and carry out a range of other less obviously military tasks - necessarily depended less on military power alone than on trade and commerce, diplomacy and cultural influence to avoid constant conflict. It is ironic, therefore, that much of the pressure on the frontier came not from forces who were hostile to the empire, but from those who wished to be part of the Roman state but who found that they were threatened by others behind them or rejected as barbarians by the culture they admired. This is, perhaps, to formulate the issues far too simplistically, but there is nevertheless an important element of truth here. By the same token, wars of conquest and then of containment into the third century CE had familiarised Roman armies and strategists with Germanic peoples and tactics, and Roman diplomacy, power-politics and cultural influence had all worked to maintain a degree of stability. From the late third century in particular, however, a series of developments across the broader Eurasian context destabilised these arrangements.
Germanic peoples had been on the move since the first century BCE, migrating from Scandinavia into north-eastern and central Europe. By the middle of the second century some had arrived in the Pontic steppe north of the Black Sea and others had settled west of the Carpathians. A short-lived stability was reached with the establishment by the Ostrogoths and Visigoths of semi-nomadic pastoralist confederacies which evolved in contact with nomadic groups, such as the Iranian Alans, in the regions north of the Black Sea across to the Caspian. But while the Visigoths occupied a restricted region in what is now the western Ukraine and Romania, the Ostrogoths dominated the whole area from the Crimea up through the Ukraine and north to the shores of the Baltic, whose indigenous, largely Slav populations were made tributary.
Other groups had been under Roman influence for far longer, including the various west Germanic peoples described by Tacitus, for example, and with whom the Romans had had both friendly and hostile relations over the centuries. Some of these had been absorbed into Roman territory; the majority had by the fourth century come to form a series of independent, often competing but still Roman-influenced tribal entities along and behind the Rhine, again exercising tributary authority over many smaller groups, both Slav and Germanic. The two largest groups in the west were the Franks (along the northern and central Rhine), with the Burgundi - an eastern Germanic group - and the Alemanni (to their south). But associated with the latter in particular, and stretching along the upper Rhine and Danube, were the Marcomanni and the Quadi. Behind these groups the Jutes, Angles and Saxons in the north, the Lombards and Thuringi in the centre, and the Vandals, Gepids and Heruls in the south and east were also in frequent conflict with one another and with the dominant tribes. Raids across the frontier, or in the case of the northern groups, across the North Sea into Britannia, became increasingly frequent during the later fourth century, but pressure on the frontier and warfare with the various Germanic groups had always been a factor of Roman imperial existence. Marcus Aurelius had defeated the Marcomanni in the second century, Frankish and Alemannic raids had been common during the third century, and in the 350s and early 360s a Frankish-Alemannic attack was defeated by Julian.
This situation was transformed by the arrival of the Huns, however, who appeared on the borders of the Ostrogothic world in the late 360s CE. A mixed group of Turkic and Mongol tribes which had arisen out of the collapse of the great Hsiung-Nu confederacy on the eastern and central steppe in the first century CE, the Huns split during the fourth century into two major sub-factions, the White Huns, also called the Hephthalites, who invaded Iran from the north-east and caused substantial disruption and devastation, and the Black Huns, who set the Germanic peoples in motion - partly in response to Ostrogothic attempts to extend their control eastwards. The clash resulted in the rapid destruction of the Ostrogothic and Visigothic confederacies and the expansion of the Huns to the Danube by the early fifth century. In turn this set in motion the other Germanic peoples, and the enormous pressure this placed on Roman defences finally led to the collapse of the western frontiers and the occupation of large stretches of the western provinces by Germanic groups, initially as federates granted land and protection in return for military service, then as occupiers and conquerors. The breaching of the Rhine frontier by the Suevi, Vandals and Alans and their move into southern Gaul and then Spain, the Visigothic invasion of the Thracian provinces in the 370s and their subsequent move first into Italy (Rome was sacked in 410), and then on to southern Gaul and Spain, the occupation of the region of Tunisia by the Asding Vandals who had fled the new Visigoth masters of Spain in the 420s, and the Frankish and Burgundian occupation of northern and eastern Gaul, all followed from this new international situation.
In eastern Europe the movement of the Slav peoples is related to, but slightly later than, these developments. By the middle of the sixth century the eastern empire was becoming familiar with the raiding of small bands of Slavs, and during the second half of the century it became clear that many of these bands were intent on permanent settlement wherever they could find suitable unoccupied land, or drive the indigenous population off. But the small, disorganised, if numerous, bands of Slavs were soon overwhelmed by the more aggressive Avars, a Turkic people whose dominant clan (known in Chinese sources as the Juan Juan) had been chased off their pastures by their former subordinates, the Blue Turk confederacy, and had fled westwards. Allying themselves with other disparate nomad groups they appeared on the empire’s borders in the 560s, and by the 580s had become a serious threat to imperial power in the Balkans.
Map 2.2 Migrations and invasions: Huns, Germans and Slavs.
World History
