The historical point of departure for this volume is Charlemagne's ill-fated incursion into Spain in 778. After an unsuccessful siege of Zaragoza, the king of the Franks directed his army north and on his passage through the Pyrenees, he turned his wrath on Pamplona, destroying the Basque city and its walls. The Basques subsequently ambushed the rearguard of Charlemagne's army on the heights of Pyrenees, killing numerous officers of the palace, plundering the baggage, and then vanishing into the forested hills, leaving the Franks to grieve without the satisfaction of revenge. In Spain,...