The Holy Roman Empire was a multi-ethnic complex of territories in central Europe that developed during the Early Middle Ages and continued until its dissolution in 1806. On 25 December 800, Pope Leo III crowned the Frankish king Charlemagne as Emperor, reviving the title in Western Europe, more than three centuries after the fall of the Western Roman Empire. The title was revived in 962 when Otto I was crowned emperor, fashioning himself as the successor of Charlemagne, 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 constituting the empire, the office of Holy Roman Emperor was traditionally elective, although frequently controlled by dynasties. Emperor Francis II dissolved the empire on 6 August 1806, after the creation of the Confederation of the Rhine by Napoleon, before 1157, the realm was merely referred to as the Roman Empire. In a decree following the 1512 Diet of Cologne, the name was changed to Holy Roman Empire of the German Nation, by the end of the 18th century, the term Holy Roman Empire of the German Nation had fallen out of official use. As Roman power in Gaul declined during the 5th century, local Germanic tribes assumed control, by the middle of the 8th century, however, the Merovingians had been reduced to figureheads, and the Carolingians, led by Charles Martel, had become the de facto rulers. In 751, Martel’s son Pepin became King of the Franks, the Carolingians would maintain a close alliance with the Papacy. In 768 Pepin’s son Charlemagne became King of the Franks and began an expansion of the realm. He eventually incorporated the territories of present-day France, Germany, northern Italy, on Christmas Day of 800, Pope Leo III crowned Charlemagne emperor, restoring the title in the west for the first time in over three centuries. After the death of Charles the Fat in 888, however, the Carolingian Empire broke apart, according to Regino of Prüm, the parts of the realm spewed forth kinglets, and each part elected a kinglet from its own bowels. After the death of Charles the Fat, those crowned emperor by the pope controlled only territories in Italy, the last such emperor was Berengar I of Italy, who died in 924. Around 900, autonomous stem duchies reemerged in East Francia, on his deathbed, Conrad yielded the crown to his main rival, Henry the Fowler of Saxony, who was elected king at the Diet of Fritzlar in 919. Henry reached a truce with the raiding Magyars, and in 933 he won a first victory against them in the Battle of Riade, Henry died in 936, but his descendants, the Liudolfing dynasty, would continue to rule the Eastern kingdom for roughly a century. Upon Henry the Fowlers death, Otto, his son and designated successor, was elected King in Aachen in 936 and he overcame a series of revolts from an elder brother and from several dukes. After that, the managed to control the appointment of dukes. In 951, Otto came to the aid of Adelaide, the queen of Italy, defeating her enemies, marrying her. In 955, Otto won a victory over the Magyars in the Battle of Lechfeld
An illustration from Schedelsche Weltchronik depicting the structure of the Reich: The Holy Roman Emperor is sitting; on his right are three ecclesiastics; on his left are four secular electors.
Double-headed eagle with coats of arms of individual states, symbol of the Holy Roman Empire (painting from 1510)