In the West during the Middle Ages and beyond, the idea of empire was driven by the history of Rome as understood from the works of Roman historians and the survival of imperial material civilization. Although the Roman experience, in general, served as the imperial touchstone for Europeans, it was the later or more specifically the Christian Roman empire, which gradually emerged following the edict of toleration issued by emperor Constantine I (r. 306–37) at Milan in 312, that served to animate the future of the imperial idea. A matrix of images of the later Roman empire in the West was vitalized by the famous ‘coronation’ of Charlemagne (d. 814) at Rome on Christmas day 800. Subsequently, the efforts of the Ottonian dynasty, especially under Otto the Great (r. 936–73), maintained this process, first in regard to the so-called German empire and later (as Len Scales discusses in Chapter 10) the Holy Roman Empire.

The imperial idea was a subject of ongoing interest. This was especially the case in regard to those medieval rulers and their advisers who worked diligently to connect Rome's successor states to its erstwhile empire through what scholars have come to call imitatio imperii. Of importance to this process of maintaining a more or less close identification with the imperial past were a variety of religious ceremonies. These included traditional Latin prayers for the health of the ruler and his family, and for the success of his administration of the state. Perhaps the most elaborate ceremonies were those quasi-religious efforts engineered to celebrate military victories. Coinage, both denominationally with the continued use of solidi and denarii and in terms of images and legends, was yet another means by which the governments of Rome's early medieval successor states consciously maintained both ideological and material continuity with the imperial past.

The Later Roman Legacy

In a more mundane sense, and especially in Gaul, the later Roman empire left an enduring material and institutional inheritance to the Middle Ages. This included a large number of fortified cities and towns, a magnificent system of roads and bridges and excellent port facilities. However, the most important imperial legacy, at least from an administrative perspective, was the civitas, which later was often called the pagus (pl. pagi).