The Holy Roman Empire, which has been referred to as such since the High Middle Ages, was considered the quintessential empire even in the Middle Ages. It distinguished itself fundamentally from all other Western imperial formations not only through its connection with the imperial authority but also through the role assigned to it in the Christian world order. With the coronation of Charlemagne in 800, the West gained its own empire, closely linked to Rome and the papacy, thereby emancipating itself from the Greek Orthodox-influenced Byzantine Empire. The restoration of the Western Empire by Otto the Great in 962 led to a lasting connection between the Roman imperial dignity and the German kingship. This work defines the concepts of empire and imperial authority from political, legal, constitutional, and intellectual historical perspectives.