of prince electors surround the
imperial coat of arms; from a 1545 armorial. Electors voted in an Imperial Diet for a new Holy Roman Emperor. in a 12th-century stained glass window,
Strasbourg Cathedral, now at
Musée de l'Œuvre Notre-Dame. From the time of
Constantine I (), the
Roman Emperors had, with very few exceptions, taken on a role as promoters and defenders of
Christianity. The
reign of Constantine established a precedent for the position of the Christian emperor in the
Great Church. Emperors considered themselves responsible to God for the spiritual health of their subjects, and after Constantine they had a duty to help the Church define and maintain
orthodoxy. The emperor's role was to enforce doctrine, root out
heresies, and uphold ecclesiastical unity. Both the title and connection between Emperor and
Church continued in the
Eastern Roman Empire throughout the medieval period (
in exile during 1204–1261). The
ecumenical councils of the 5th to 8th centuries were convoked by the
Eastern Roman Emperors. In
Western Europe, the title of
Emperor in the West lapsed after the death of
Julius Nepos in 480, although the rulers of the
barbarian kingdoms continued to recognize the authority of the Eastern Emperor at least nominally well into the 6th century. While the reconquest of
Justinian I had re-established
Byzantine presence in the Italian Peninsula, religious frictions existed with the
Papacy who sought dominance over the Church of
Constantinople. Toward the end of the 8th century, the Papacy still recognised the ruler at Constantinople as the Roman Emperor, though Byzantine military support in Italy had increasingly waned, leading to the Papacy to look to the
Franks for protection. In 800
Pope Leo III owed a great debt to
Charlemagne, the
King of the Franks and
King of Italy, for securing his life and position. By this time, the Eastern Emperor
Constantine VI had been deposed in 797 and replaced as monarch by his mother,
Irene. Under the pretext that a woman could not rule the empire, Pope Leo III declared the throne vacant and crowned Charlemagne Emperor of the Romans (), the successor of Constantine VI as Roman emperor, using the concept of
translatio imperii. The title of emperor in the West implied recognition by the pope. As the power of the papacy grew during the Middle Ages, popes and emperors came into conflict over church administration. The best-known and most bitter conflict was that known as the
investiture controversy, fought during the 11th century between
Henry IV and
Pope Gregory VII. After the coronation of Charlemagne, his successors maintained the title until the death of
Berengar I of Italy in 924. The comparatively brief interregnum between 924 and the coronation of
Otto the Great in 962 is taken as marking the transition from the
Frankish Empire to the
Holy Roman Empire. Under the
Ottonians, much of the former
Carolingian kingdom of
Eastern Francia fell within the boundaries of the Holy Roman Empire. Since 911, the various
German princes had elected the
King of the Germans from among their peers. The King of the Germans would then be crowned as emperor following the precedent set by Charlemagne, during the period of 962–1530.
Charles V was the last emperor to be crowned by the pope, and his successor,
Ferdinand I, merely adopted the title of "Emperor elect" in 1558. The final Holy Roman emperor-elect,
Francis II, abdicated in 1806 during the
Napoleonic Wars that saw the Empire's final dissolution. The term
sacrum (i.e., "holy") in connection with the German Roman Empire was first used in 1157 under
Frederick I Barbarossa. The Holy Roman Emperor's standard designation was "August Emperor of the Romans" (
Romanorum Imperator Augustus). When Charlemagne was crowned in 800, he was styled as "most serene Augustus, crowned by God, great and pacific emperor, governing the Roman Empire," thus constituting the elements of "Holy" and "Roman" in the imperial title. The word
Roman was a reflection of the principle of
translatio imperii (or in this case
restauratio imperii) that regarded the Holy Roman emperors as the inheritors of the title of emperor of the
Western Roman Empire. In German-language historiography, the term
Römisch-deutscher Kaiser ("Roman-German emperor") is used to distinguish the title from that of
Roman emperor on one hand, and that of
German emperor (
Deutscher Kaiser) on the other. The English term "Holy Roman Emperor" is a modern shorthand for "emperor of the Holy Roman Empire" not corresponding to the historical style or title, i.e., the adjective "holy" is not intended as modifying "emperor"; the English term "Holy Roman Emperor" gained currency in the interbellum period (the 1920s to 1930s); formerly the title had also been rendered as "German-Roman emperor" in English. ==Succession==