Aside from the emotional costs of migration, financial ones were also a major factor in any migrant’s calculations. Most first-millennium migration that we know anything about was a question, more or less, of walking and wagons. It involved no major transportation costs, apart from wear and tear to animals, peoples and wheels, and participation was consequently open to many. It nonetheless involved many indirect costs, above all the potential food shortages that were bound to result when movement disrupted normal agricultural activity. As a result, food stocks had to be maximized before moving, unless circumstances were completely overwhelming, and this meant that autumn was the classic moment to make a move – just after the current year’s harvest had been gathered and while there was still a chance of some grass growing to feed the oxen pulling the wagons and other animals. Alaric’s Goths moved into Italy in both 401 and 408 in the autumn, Radagaisus’ Goths in autumn 405. The Vandals, Alans, and Sueves who crossed the Rhine at the very end of 406 likewise presumably began their trek from the Middle Danube in the autumn of that year.10
As usual, there is little information about the impact of migration costs beyond this very basic point, but logistic problems do show themselves from time to time in the available data. Above all, extended periods of movement left groups particularly vulnerable in economic terms. Flavius Constantius was able to bring Alaric’s Goths – now led by Athaulf and Vallia – to heel by starving them out in 414/15. By that date, they had been living off the land without planting crops for six or seven years. Later in the fifth century, similarly, after the collapse of the Hunnic Empire, the surviving sources give us just a little insight into the logistic strategies adopted by Theoderic the Amal. His grouping journeyed around the Balkans with wagonloads of seedcorn in the 470s, and one dimension of its diplomatic negotiations with the Roman state involved providing it with agricultural land. Even on the march, noticeably, this group always sought to establish more regular economic relationships with Balkan communities, rather than merely robbing them. This meant that the communities could keep on farming and producing surpluses, from which the Goths could siphon off a regular percentage, whereas destroying them by pillage would only have fed Theoderic’s followers once.
Logistic factors had a still bigger impact upon population flows requiring more than land transport. Mass access to sea transport did not even become a possibility until the advent of steerage class in the enormous transatlantic liners of the later nineteenth century. Before that point, travel costs necessarily limited participation in any kind of maritime-based expansion. Again, the Viking period provides the best-documented first-millennium example. Ships were highly expensive, and even specialist cargo ships could carry only limited numbers of people and their goods. Thus Viking raiding required the less well-off to come to some kind of joint arrangement for funding the purchase or hire of a ship (though how many shipowners, I wonder, would be willing to hire out shipping for raiding ventures?), or to attach themselves to a leader of higher status.11 Logistic limitations figured even more strongly when it came to the settlement phases, when so many more types of people and a wider range of bulky farming equipment were required. The relevant shipping costs alone make Stenton’s suggested phase of large-scale Norse peasant settlement in the Danelaw pretty much inconceivable. Who would have bothered to pay for this when there was a subdued, low-status Anglo-Saxon labour force already in situ? We also see the effects of logistics on the Icelandic settlements, where each immigrant unit was headed by a higher-status individual who could presumably cover the large initial investment costs of transportation. Logistics may also have limited the number of Scandinavian women who participated in the Norse migration flow compared to the other land-based movements of our period. Modern DNA patterns suggest that only one-third of immigrant women to Iceland came all the way – directly or indirectly – from Scandinavia, with the rest moving a shorter distance from the British Isles. This may reflect the fact that it was too expensive for more than a minority of warriors to bring their Scandinavian sweethearts with them. On the other hand, given that the men involved were relatively wealthy, and that they were pagan and polygamous, it may be that women outnumbered men early on, with each Scandinavian male bringing with him not only his Scandinavian sweetheart but a couple of British or Irish babes besides.
As frustratingly limited as all the Viking-period evidence is, our other major first-millennium examples of maritime movement – Anglo-Saxon moves across the North Sea and the expedition of Vandals and Alans across the Straits of Gibraltar – are not even illuminated in this much detail. The impact of logistic demands must, though, have been similar. Possibly the Vandals and Alans were in a position to use intimidation to requisition some transport, but I doubt that they were able to avoid having to meet most of their costs themselves. And there is reason to think that the fact that they could only move a relatively few people at a time dictated their initial choice of landfall: Morocco, far away from the better-defended heartland of Roman North Africa, which was their ultimate destination. The logistic impossibility of moving many people at once was probably also a major factor in the drawn-out nature of Anglo-Saxon migration into southern Britain.
So far, so good: there are a whole series of ways in which the comparative literature sheds light on first-millennium migration, even given the limited data set available. But this still leaves some big questions to answer. Above all, can we in fact accept what the sources appear to be telling us: that the first millennium occasionally saw large, mixed, and organized population groups take to the road? And, if so, how are we to explain this phenomenon both in its own context, and the fact that it has not been observed in more modern and better-documented eras? Again, modern migration studies, in my view, can help answer these questions, but a fully satisfactory explanation also requires us to explore first-millennium migration patterns against the backdrop of a much wider set of transformations that were unfolding simultaneously in barbarian Europe.
MIGRATION AND DEVELOPMENT
Comparative studies provide two basic points of orientation when thinking about the likely causes of any observable migration flow. First, it is overwhelmingly likely that a substantial difference in levels of economic development between adjacent areas will generate a flow between the two, from the less-developed towards its richer neighbour. What ‘adjacent’ means will vary enormously in different eras according to what transport is available, and a situation that would otherwise generate a ‘natural’ flow of people may be interfered with by political structures at either end, or by the availability of information. All things being equal, however, a flow of population will be one result of different levels of development, the result of Homo sapiens sapiens’ inherent tendency to use movement as a strategy for maximization. The second point is equally basic. In the vast majority of cases, the precise motivation of any individual migrant will be a complex mixture of free-will and constraint, of economic and political motives. There are exceptions, not least when political refugees are driven forward by fear of imminent death, but most migrants are motivated by some combination of all four factors. Taken together, what both of these observations stress above all is that migration will almost always need to be understood against prevailing patterns of economic and political development. Taking this approach, in my view, provides satisfactory explanations for both the general geographical ‘shape’ of first-millennium migration, and the seemingly odd nature of its characteristic migration units.
Migration in Roman Europe
At the start of the first millennium, the most highly developed region of Europe – in both economic and political terms – was the circle of the Mediterranean united under Roman domination, to which the largely La Tène landscapes of the south and west had recently been added. La Tène Europe featured developed agricultural regimes whose surpluses could support relatively dense populations, together with considerable production and exchange in other sectors of the economy. The Romans did not only conquer La Tène populatio
ns as they moved north, but it is a fact – and not an accidental one – that their conquests ran out of steam more or less at the outer fringes of La Tène Europe. The reason was simple: beyond that zone, the profits of conquest ceased to be worth the costs. Beyond La Tène Europe lay the territories of the largely Germanic-speaking post-Jastorf world. There was a large degree of variation in economic patterns across this zone, not least because some of its populations had been in substantial engagement with their La Tène neighbours for a considerable period. In general terms, however, political units were smaller in scale here than those of La Tène Europe, even before the latter was incorporated into the Roman Empire, and agricultural productivity was lower. General population density was therefore less, and there are fewer signs either of non-agricultural production and exchange, or of marked differences of wealth (at least as expressed in material cultural terms). Beyond Jastorf Europe, the northern and eastern reaches of the European landscape were still host to Iron Age farming populations (as far as ecological conditions permitted), but they operated still less productive agricultural regimes, their settlements were smaller and even more short-lived, and they possessed little in the way of material cultural goods.
Faced with this distinctly three-speed Europe (Map 1), comparative migration studies would lead you to expect flows of population from its less developed regions to the more developed (i.e. in broadly southerly and westerly directions). And in the Roman period – the first three centuries AD – this is essentially what occurred. The economic and sociopolitical structures of more developed Roman Europe sucked in population from its less developed neighbours in a variety of forms, particularly from adjacent, largely Germanic-dominated post-Jastorf Europe. Many individuals entered the Empire as voluntary recruits for Roman armies on the one hand, or involuntary slaves for a variety of economic purposes on the other. These population flows are well known and require no further comment here. But the larger and more contentious Germanic population flows of the second and third centuries also fall into line with this pattern, in the general sense that they too moved broadly south and west towards more developed Europe. A full understanding of their particular history, however, also requires an understanding of how a broader set of interactions with the Roman Empire had in the meantime been transforming the three-speed pattern which prevailed at the birth of Christ.
For one thing, the military and political structures of the Roman Empire fundamentally explain the geographically asymmetrical outcome of Germanic expansion in these years. The forces behind the expansion seem to have been operating very generally in Germanic-dominated central Europe, but the resulting population flows had much more dramatic effects in the south-east, and particularly north of the Black Sea, than in the south-west. Where Germanic immigrants took over no more than the Agri Decumates in the south-west, further east Dacia was abandoned and political structures north of the Black Sea were entirely remade. There may have been some difference in the scale of the migratory flows in operation in each direction, but this, too, was reflective of the more fundamental cause of the different scale of outcome. Flows south and east were operating against the clients of Rome’s inner frontier zone, rather than directly against the military power of the Empire itself. As a result, the likelihood of success was that much greater than in the south-west, where the Empire’s military power had to be tackled directly.
Why the successful leaders of these expansion flows were generally willing to settle for outcomes that left them largely on the fringes of Empire, instead of pressing on permanently across the frontier, also comes down in part to the longer-term effects of interaction with the Roman world in the first two centuries AD. The operations of trading mechanisms – both in longer-distance luxury goods and shorter-distance largely agricultural products – opportunities for raiding richer Roman territories, and the Empire’s own propensity for bolstering the power of its clients with diplomatic subsidies all meant that in the first two centuries of the Empire’s existence new wealth built up at the courts of Germanic kings in the immediate vicinity of the frontier. Three-speed Europe thus developed a fourth gear in the form of an inner zone of clients whose wealth outstripped those of their former peers in what now became the outer periphery of post-Jastorf Europe. Not only was it militarily much less dangerous for the leaders of Germanic expansion to restrict their operations to areas beyond the imperial frontier, but two centuries of interaction with the Empire, and the subsequent accumulations of wealth, had made the frontier zone an attractive target for predatory expansion in its own right. Before these processes had unfolded, there would have been little point for ambitious Germanic warlords in moving, say, from northern central Europe to southern central Europe, or from north of the Carpathians to the south-east, since the potential material gains for such efforts would have been minimal.
Understanding the action of the later second and third centuries in this way also explains the apparently odd form taken by at least some of the units participating in these migration flows. The first recorded attempt from the outer periphery to tap into the new wealth building up closer to the imperial frontier took the form of a raid. As the power of King Vannius of the Bohemian-based Marcomanni weakened in his dotage, an ousted political rival was able to organize a warband from central Poland (and possibly northern Poland too) to ransack the movable wealth around his court, much of it the proceeds of diplomatic subsidies and his cut from the activities of Roman merchants. Although I cannot prove it, I would be willing to bet that this was but one example of a far from uncommon phenomenon. Hit-and-run raids were not, however, the most effective way to tap into all the new wealth accumulating in the immediate hinterland of the Empire. For entirely structural reasons to do with trade, Roman diplomatic methods and even ease of raiding Roman territory, the best opportunities to benefit from the new wealth-generating interactions with the Roman Empire were all limited geographically to the immediate frontier zone, and any greater ambitions towards wealth acquisition among groups and leaders in the outer periphery required their permanent relocation towards the frontier. It is therefore hardly surprising that raiding gave way to migration in the second and third centuries as more ambitious leaders and followings from the outer periphery looked to win control of the new Rome-centred wealth flows operating in barbarian Europe.
But by the end of the first century AD, there was no potentially lucrative spot along the frontier that was not already occupied by a warlord of some kind, and no sitting tenants were likely to surrender their highly advantageous position without a fight. Any permanent relocation towards Rome’s frontier therefore necessarily required the destruction of existing political structures, and this explains why the second- and third-century migration flows eventually encompassed substantial military forces numbered in the thousands, rather than warbands of just one or two hundred men. Warbands might raid effectively enough, but their power was insufficient to remake an entire political structure, so that ambitious wannabes from the outer periphery had no choice but to recruit larger expeditionary forces to achieve their aims.
It is worth pausing to consider this pattern of migratory expansion in the light of more recent and better-documented examples. This kind of intentional, predatory intrusion on the part of thousands of armed individuals is not generally seen in the modern world, and this is sometimes put forward as an objection to supposing that it ever occurred in the past. Half of the answer to this objection is that, though not common, this kind of activity has indeed been seen in the relatively modern world: it is exactly the same basic kind of migratory pattern observable among the Boers of the Great Trek. In that case, the intrusive units could be smaller because the Boers enjoyed a massive advantage in firepower over their Zulu and Matabele opponents. In the second and third centuries, any technological advantage was probably more likely to have lain with the groups of the inner periphery being targeted, since they may well have been buying Roman weaponry, so that the intrusive forces from the outer periphery had to be
more or less as large as those deployed by the sitting kings of the frontier region.
The other half of the answer comes from thinking about precisely why modern migratory flows, even if cumulatively large, tend to operate on the basis of small individual migration units of just a few people at a time. They do so because the migration-unit size is dictated by the way in which modern migrants seek to access wealth from the more-developed economies to which they have been attracted. In the modern context, wealth is accessed by individual immigrants finding employment in the industrial or service sectors of an economy, which is well-paid at least from the relative perspective of the immigrant him-or herself. The underlying principle here is not that migration-unit sizes are always likely to be small, but, rather, that they will be appropriate to the means by which the wealth of the more developed economy is going to be accessed. All the economies of first-millennium Europe were essentially agricultural, and extremely low-tech. As a result, even in the developing periphery of the Roman Empire, they did not offer many even relatively well-paid jobs for individual migrants, except for a few who could attach themselves to the military followings of frontier kings. For those with ambitions to unlock the wealth of this world on a much larger scale, coming as an individual immigrant, or merely within a small group, was a pointless exercise. In such a context, you had to arrive with enough force to defeat the sitting tenant, and prompt the Empire to identify you now as its preferred trading and diplomatic partner on your particular sector of the frontier. Although this kind of migrant group is not commonly seen in the modern world, therefore, it actually accords with the fundamental principles behind all observed migration flows. Large-scale predatory intrusion was as appropriate to wealth acquisition via migration in the first millennium, as individual movement is now.
Empires and Barbarians Page 78