When empires lost their grip on peripheral areas, new political communities could emerge. Often, they were ruled by military elites from outside the empire, who had been more or less involved with its defence system. Frequently, a political landscape of the ‘middle ground’ evolved, with several competing political centres and considerable extension into the barbarian fringes of the imperial system. These ‘sub-imperial’ powers could remain in an unstable balance with the empire, they could eventually replace it, or be drawn into the imperial sphere again. Comparing a number of late antique and medieval Eurasian test cases may offer insights into the dynamics of such constellations. Such new political powers usually faced similar challenges, but relied on rather different structures, with widely different outcomes. The most obvious differences lay in their self-representation and outside perception. Many relied on dynastic legitimacy, many on ethnic identification, often also in combination. All of them sought imperial legitimation, though to very different degrees; a few also claimed imperial status themselves. Most of these polities where rather short-lived, either because the central imperial power recovered or because new ‘barbarian’ groups replaced them. But even if the centrifugal forces disappeared, they might have an effect on the new configuration of the empire. Some of the peripheral polities turned into rather stable entities, and new centres of gravitation evolved. In Europe, a rather persistent landscape of ethnic polities emerged, first in the West, then also in parts of the orthodox world and in Northern and Eastern Central Europe. In Asia, on the other hand, dynastic polities kept succeeding each other, whether in imperial guise or not. This is an obvious difference in long-term development that may serve as a point of departure for the analysis of other variables.
