The conclusion draws upon the findings of all the chapters to argue that Barbarossa scholars had often studied more a construct of post-Kulturkampf Germany than the medieval emperor himself. Rather than a sacraliser of the state who teamed up with Reichskanzler Rainald of Dassel (a stand-in for Otto von Bismarck) in order to hammer the Papacy into submission, Frederick I was a ruler determined to restore the greatness of the Empire by many different means, including papal and Arab alliances. This has been overlooked because of the dearth of sources for the later part of his reign, and because of the profound misunderstanding of Frederick’s Aquensian projects. By dismantling the historiography in an archaeological way, Sulovsky restores the connections apparent in the sources, and makes it clear that the increasing Romanisation of the Empire had radical consequences for authority and its expressions, both for the pope and the emperor. Therefore, much of what was described as a deliberate sacralisation of the Empire in opposition to the Papac, was in fact its gradual Romanisation. This was not a project spearheaded by German court, but by the self-conscious Italians, who wanted a Roman emperor to represent them, and not a German king.

The introduction explains the state of the scholarship regarding the sanctity of the state, starting with what is commonly believed. Sulovsky then traces the argument back to its intellectual roots, in the process showing that it is based on false premises that had more to do with the clash of Catholic and Protestant worldviews than with any medieval reality per se. The introduction of the phrase sacrum imperium, the translation of the Three Kings and the canonisation of Saint Charlemagne constituting a triad of sacralising acts is traced to Heinrich Appelt, the senior diplomatist who edited Frederick I’s diplomata. However, as Sulovsky shows, Appelt drew heavily upon Friedrich Heer, whose magnum opus Die Tragödie des Heiligen Reiches deeply influenced many scholars, though he is only reluctantly cited by them. Heer’s work is then shown to be a Catholic response to the Kulturkampf-dominated Prussian school, which formulated the original idea of the sacralisation of the state in 1910, but based on eighteenth-century German Protestant interpretations of imperial history. Thus, the introduction demonstrates that much of our knowledge rests on the presuppositions and axioms of a bygone ideological struggle.

The penultimate chapter is about the reliquary shrine of Saint Charlemagne known as the Karlsschrein. It explores both the political and the religious significance of the monument and how the local convent, the city and the imperial court all participated in its making. By delving deep into the history of Aachen and its surrounding region, the ex-Kingdom of Lotharingia, Sulovsky shows how every single inconsistency was deliberately chosen to make a political or religious point. Thus, where previous scholars only focused on the major figures on the shrine, this book presents dozens of overlooked depictions both of symbolic animals and of humans, including representations of the local community. Moreover, where scholars struggled to find an exact purpose for the shrine’s appearance, the author makes it clear that the papal–imperial negotiations for the introduction of hereditary monarchy served as the foundation for the new vision of the Holy Roman Empire. Indeed, the Karlsschrein is shown to refer not only to Charlemagne’s foundation of the city and church of Aachen, and also of the Empire, but to the centuries-long papal–imperial alliance.