The Changing Concept of Roman Imperium: from Late Antiquity to the Middle Ages

The concept of Imperium, an important foundation for imperial Rome, survived the western empire and left an enduring legacy on Europe. Through late antiquity's struggle to preserve Imperium and subsequent Carolingian and German attempts to appropriate and change the concept, Imperium continually evolved to fit or confound those who wished to possess it. On the sidelines of the rulers we see reflections of their efforts, the interplay with religious concerns, and the practical limitations of the medieval concept through texts like Justinian's Institutes, the Chronicon of Theitmar of Marseburg, and the Memoriale de Prerogativa Imperii Romani from Alexander von Roes.