The Holy Roman Empire was a multi-ethnic complex of territories in central Europe that developed during the Middle Ages and continued until its dissolution in 1806. The core and largest territory of the empire was the Kingdom of Germany, though it included at times the Kingdom of Italy, the Kingdom of Bohemia, and the Kingdom of Burgundy, as well as numerous other territories. The empire grew out of East Francia, a primary division of the Frankish Empire. On Christmas Day 800, Pope Leo III crowned the Frankish king Charlemagne as Emperor, reviving the title in Western Europe after more than three centuries. After Charlemagne died, the title passed in a desultory manner during the decline and fragmentation of the Carolingian dynasty, eventually falling into disuse by 924. The title was revived in 962 when Otto I was crowned emperor, fashioning himself as the successor of Charlemagne and beginning a continuous existence of the empire for over eight centuries. Some historians refer to the coronation of Charlemagne as the origin of the empire, while others prefer the coronation of Otto I as its beginning. Scholars generally concur, however, in relating an evolution of the institutions and principles comprising the empire, describing a gradual assumption of the imperial title and role.