In part, the fall of west Rome (and that of the Roman east too, for that matter) has to be understood as the playing-out of the full consequences of development processes that had been at work throughout the half-millennium of the Empire’s existence. Much of the new strategic pattern that prevailed across the European landscape from around 500 AD was dictated by the emergence of a supraregional power block in northern Europe made possible by the transformations of the previous five hundred years. As we have seen, in the late fifth century the Franks emerged as a new force in the old Empire’s inner periphery. They proceeded to combine their original homelands with former imperial territory west of the Rhine and other parts of Rome’s inner and outer peripheries. The resulting imperial power block was the first of its kind based on the exploitation of northern, non-Mediterranean, European resources. There is a very real sense, therefore, in which the Roman Empire, in the long term, sowed the seeds of its own destruction. Its economic, military and diplomatic tentacles transformed adjacent populations until they were strong enough to rip it apart.
But if the nature of Empire after Rome was in one sense almost predictable, the usual dose of historical accident also played its part. Thinking about the patterns of transformation in the round, then what you might have expected to see was fringe pieces of Roman territory falling into the hands of ever more ambitious and aggressive frontier dynasts as, over time, economic and political change increased the power at their disposal and slowly eroded the initial power advantage that had allowed the Empire to establish such widespread dominion in the first place. Indeed, such a sequence of events did begin to unfold in the Roman period. In the third century, Transylvanian Dacia and lands between the Carpathians and the Danube had to be ceded to the Goths and other new powers of the Empire’s east European periphery, while in the west Alamanni took possession of the abandoned Agri Decumates. In the fourth century, in similar vein, a particularly aggressive king of the Alamanni such as Chnodomarius could extend his control to the western side of the Rhine valley, and Salian Franks made moves on land west of the lower Rhine frontier. At this point, imperial power was still strong enough to keep such ambitions in check, but the tendency is clear enough.
Instead of following anything like this scenario, however, the rise and fall of Hunnic power generated an unprecedented degree of politically motivated migration, which caused a sudden and unpredictable relocation on to Roman soil of militarily powerful groups from parts of its inner and outer peripheries. The first crisis of 375–80 saw Goths, Sarmatians and Taifali enter Roman territory from the inner periphery beyond the Lower Danube frontier region, to be followed in 405–8 by some of their Middle and Upper Danubian counterparts: the Sueves (if they were Marcomanni and Quadi) and Burgundians. Amongst groups from the outer periphery caught up in the same events we can number Alans, different groups of whom entered imperial territory both in 375–80 and again in 405–8, accompanied in the later crisis by Hasding and Siling Vandals, who hovered somewhere between the inner and outer peripheries – their territories were not that far from the frontier, but we know of no diplomatic relations between them and the Empire before the convulsions of the Hunnic era.64 These migrations caused the western Empire to suffer sudden and catastrophic losses of tax base in its heartlands, which in turn precipitated the total and equally rapid collapse of its military and political systems.
Instead of a new supraregional power emerging gradually in northern Europe as competitive dynasts slowly built up their domain, biting off chunks of imperial territory while outfacing their peers beyond the frontier, the intervention of the Huns dramatically altered both the timing of the process and, at least in part, its nature. In the fourth century, the far boundary of Rome’s outer periphery, dominated by largely Germanic-speaking groups and characterized by very particular kinds of material-cultural systems, stretched over a vast expanse of territory. In the sixth century, after the migrations of the Hunnic era and the associated collapse of the Przeworsk, Wielbark and Cernjachov systems, the old patterns of material culture could no longer be found east of the Elbe or outside of the Middle Danube basin. Nor is there any sign in the historical sources of the substantial political structures that had previously existed there in the Roman period. West Roman imperial collapse was thus accompanied by a huge reduction in the extent of Germanic-dominated Europe, and the unification of most of what remained under Frankish hegemony. Both the speed of Roman collapse and the dramatic shrinking of Germanic Europe resulted from migratory processes unleashed by the Huns. In overall terms, this amounts to a dramatic sea change in European history.
When measuring the total effect of the Roman Empire and its fall upon patterns of European development, then, we are faced with some paradoxical conclusions. First, in the Roman period proper – up to, say, 350 AD – interaction with the Empire helped spread more developed political structures and more complex patterns of economic interaction across broad tranches of the European landscape. I have no idea whether this was a ‘good’ or ‘bad’ thing overall for human history. The march of civilization is not at all easy to measure. What I am confident about, however, is that it was a phenomenon of huge importance. But, second, the collapse of the Empire dramatically reduced the geographical extent of more developed Europe, as migratory processes – partly predatory in nature, partly more negative in motivation – sucked armed and politically organized groups south and west across the map. The fact that the new Frankish superpower was a weaker type of state to some extent reduced the old differential between developed and non-developed Europe that had existed in the Roman period. Nevertheless, by the sixth century, more developed Europe – counting both Empire and periphery – now encompassed a much smaller area, following the concertina-like effects of Roman imperial collapse.
In the longer term, however, this second factor would prove much less important than the breaking of Mediterranean domination across western Eurasia. The Franks started this process by building the first imperial power that northern Europe had ever seen. It was completed by the rise of Islam, which turned east Rome into the satellite state of Byzantium and broke the political and even, eventually, the cultural unity of the Mediterranean. This freed northern Europe from the long-standing patterns of political interference that had marked the ancient world order. The fall of the Roman Empire saw the birth pains of Europe because Germanic and Arab expansion between them destroyed the domination of the Mediterranean over its northern hinterland. By the end of the millennium, developed Europe and the club of Christian monarchical states would run not just to the Elbe, as 500 AD, but all the way east to the Volga. The interaction of migration and development that created this further astonishing transformation of the European landscape provides the subject matter of the remaining chapters.