In this book I have investigated both what we can know about Charlemagne and what we think we know. I have taken a fresh look at the beginnings of the Carolingian empire, and have tried to free Charlemagne's reign from the clutter of arguments, assumptions and hypotheses that have somehow become facts. In charting the formation of a European identity during Charlemagne's reign, I have explored the interaction between the practical consequences of the expansion of the Frankish empire into totally new territory and Frankish perceptions and uses of the past. The degree to which Charlemagne and the Franks at the end of the eighth century and the beginning of the ninth communicated with the past in order to form or to inform their own contemporary concerns, to heighten their sense of identity and cultural affiliations and to shape their political purpose form the conceptual framework of this book. I have endeavoured to avoid ascribing without question a phenomenon loosely described as ‘Carolingian’ to his period of rule rather than to those of his successors. Instead, I have attempted to capture the dynamism of the reign and to document the astonishing changes effected throughout the period from 768 to 814. In all this I offer a critical reassessment of the sources first produced between 747/8 and 814, not because they may or may not be more truthful than accounts produced after Charlemagne's death, from Einhard's Vita Karoli onwards, but because they have at least the merit of being contemporary. They therefore reflect something of perceptions and conditions during his reign. I have been very conscious of parallel work in progress on the Carolingian period, with books in preparation from Mayke de Jong on the reign of Louis the Pious, Stuart Airlie on the Carolingian aristocracy, Jinty Nelson on Charlemagne, and David Ganz on Einhard. Consequently, I have endeavoured to avoid trespass or overlap.