precious metals as coin – was often as important as the items themselves. The ability to acquire wealth meant the ability to redistribute it, and to be able to give gifts enforced a leader’s own social dominance. In other words, conspicuous wealth translated into active power. For these purposes, gold and silver were especially important, and were the dominant medium for storing wealth.Distribution patterns of silver coinage beyond the Roman frontier tend to vary according to the political importance of particular regions at particular times: in Germania, for instance, we find huge concentration of 70,000 silver denarii in just a few decades between the reigns ofMarcus Aurelius (r. 161–180) andSeptimius Severus (r. 193–211), when campaigning along that frontier was regular and intense. What that and other evidence demonstrates is that emperors and their generalsregularly manipulated political life in the barbaricum through economic subsidy. Yet this strategy, however necessary it might seem within the mental paradigms of Roman government and however effective it might be, was also fraught with dangers.
Raising the status of some leaders above that of their neighbours and natural peers could provide them with both means and motive for military action that they would otherwise have lacked. Leaders buttressed by Roman subsidy were able to attract more warrior clients into their following, thus enlarging the political groups they led. As with Roman soldiers, barbarian warriors were better behaved when kept employed at the tasks for which they were suited. Fighting one’s barbarian neighbours was useful in this respect, but nearby Roman provinces – with their accessible wealth and a road system that made it easy for raiding parties to move rapidly about – became a hugely tempting target when imperial attentions were preoccupied elsewhere. The attractions of Roman wealth, combined with the hostility that might be generated by periodic incursions of Roman soldiers, meant that there were strong structural reasons for barbarian attacks on the Roman frontier. These same structural reasons might occasionally inspire a particularly powerful barbarian king to conceive more grandiose plans.
Examples of this phenomenon are apparent even quite early in the history of the empire, as with the famousDacian kingDecebalus. His power was deliberately shorn up byTrajan (r. 98–117) after that emperor’s first campaigns beyond the Danube. This support, however, made Decebalus locally predominant, so that he felt able to break his agreements with the emperor and menace the imperial provinces. It took two years of costly warfare to suppress a threat that had only emerged because of imperial subsidy.The Marcomannic wars of the second century obeyed a similar dynamic. They broke out in the mid-160s for reasons that remain disputed, but they precipitated invasions into the Balkans and northern Italy by neighbours of the Marcomanni. The settlement whichMarcus Aurelius (r. 161–180) initially imposed on the region failed precisely because it punished some of the chieftains on the middle Danube and rewarded others. Favoured chieftains first threatened and then attacked their less favoured neighbours, driving them into theimperial provinces and making further imperial campaigns necessary. Third-century emperors continued to manage barbarian leaders according to these long-standing habits, but they did so from a position of much greater weakness than had their predecessors. For that reason, the third century witnessed the multiplication of barbarian disturbances all along the frontiers.
New Barbarian Confederacies
Three major barbarian collectivities appear along the imperial frontier in the third century: theAlamanni, the Goths, and theFranks. Though previously unknown to the Roman world, all three groups went on to be permanent features of late imperial politics. Of the three, the Alamanni are in many ways the easiest to