The centuries from the early ninth to the early fourteenth saw the rise and splendor of medieval civilization. They saw also the emergence of a political organization of the land which underwent little fundamental change before the end of the eighteenth century: an increase in population which stretched to its limits the agricultural resources of Europe, and the development of a pattern of cities, that remained almost unaltered until the Industrial Revolution. Not until the nineteenth century do we encounter again a period of comparable development and change.

THE INVASIONS

The period began with another wave of invaders from beyond the core areas of western and central Europe. These came from Scandinavia, westward from the fjords of Norway and the plains of Denmark to the British Isles and France, eastward from Sweden to the shores of Russia and overland to the Black Sea (Fig. 5.1). The first of these sea raiders reached the shores of western Europe before the death of Charlemagne; the last landed on those of northern Britain two and a half centuries later. Their raids were but an episode in European history, but they had, locally at least, far-reaching consequences. The sudden explosion of Nordic peoples in the ninth century is as enigmatic as that of the Tartar peoples during previous centuries. It has been attributed to political struggles within Scandinavia, to overpopulation, and to environmental change in this climatically marginal land.