He was King of the Franks from 768, King of the Lombards from 774, and the first Emperor of the Romans from 800. Charlemagne succeeded in uniting the majority of western and central Europe and was the first recognized emperor to rule from western Europe after the fall of the Western Roman Empire around three centuries earlier. The expanded Frankish state that Charlemagne founded was the Carolingian Empire.
Though crowned, as Emperor of the Romans, by Pope Leo III on Christmas Day at Old St. Peter's Basilica in Rome, he ruled from Aachen in Germany.
The coronation of Charlemagne by Pope Leo III
The Coronation of the Holy Roman Emperor was a ceremony in which the ruler of Western Europe's then-largest political entity received the Imperial Regalia from the hands of the Pope, symbolizing both the pope's right to crown Christian sovereigns and also the emperor's role as protector of the Roman Catholic Church. The Holy Roman Empresses were crowned as well.
The Holy Roman Empire was established in the year 800 under Charlemagne. Later emperors were crowned by the pope or other Catholic bishops. Charles V became the last Holy Roman Emperor to be crowned by a pope: Clement VII in Bologna in 1530. Thereafter, until the abolition of the empire in 1806, no further crownings by the Pope were held.N 1
Later rulers simply proclaimed themselves Imperator Electus Romanorum or "Elected Emperor of the Romans" after their election by the princes and coronation as German king.