Holy Roman Emperor

The Holy Roman Emperor (, ) was the elected monarch ruling over the Holy Roman Empire, a Central European state in existence during the Middle Ages and the Early Modern period. By convention the first Emperor was taken to be the Frankish king Charlemagne, crowned as Emperor of the West by Pope Leo III on 25 December 800, although the Empire itself (as well as the style Holy Roman Emperor) did not come into use until some time later. Holy Roman Emperors were crowned by the Popes up until the 16th century, and the last Emperor, Francis II, abdicated in 1806 during the Napoleonic Wars that saw the Empire's final dissolution.
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Noun
1. sovereign of the Holy Roman Empire
(hypernym) Emperor
(hyponym) Charlemagne, Charles I, Charles the Great