By the end of the ninth century, the disintegration of the Carolingian Empire began accelerating and continued until its collapse in the final quarter of the tenth century. The centralized realm Charlemagne had so masterfully forged degenerated into a series of warring states. Among the numerous descendants of Charlemagne, not one proved capable of halting the internal deterioration. The decay from within eventually rendered the empire exceptionally vulnerable to peril from without as a new and more violent series of invasions made their way into western Europe.

The Vikings and Magyars spearheaded this new wave of invasions. The Magyars were nomadic peoples from western Asia. Centuries of wanderings eventually brought them to the eastern borders of the empire. Meeting little resistance from the inept Carolingian rulers, the Magyars began raiding western Europe with impunity. Their forays carried them as far west as France and...