| Realm: | the Holy Roman Empire |
| Insigniasize: | 120px |
| Insigniacaption: | Flag of the Holy Roman Empire |
| First Emperor: | Charles I (Charlemagne) |
| Last Emperor: | Francis II |
| Style: | Holy Roman Emperor |
| Appointer: | Electors' Council |
| Began: | 25 December 800 |
| Ended: | 6 August 1806 |
The Holy Roman Emperor (German: Römisch-deutscher Kaiser, or "Roman-German Kaiser") 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. The Holy Roman Empire's origins can be traced back to the Carolingian Empire of Charlemagne. 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.
The Roman of the Emperor's title was a reflection of the translatio imperii (transfer of rule) principle that regarded the (Germanic) Holy Roman Emperors as the inheritors of the title of Emperor of the Western Roman Empire, a title left unclaimed in the West after the death of Julius Nepos in 480.
From the time of Otto the Great onward, much of the former Carolingian kingdom of Eastern Francia became the Holy Roman Empire. The various German princes elected one of their peers as King of the Germans, after which he would be crowned as emperor by the Pope. The last emperor to be crowned by the pope was Charles V; all emperors after him were technically emperors-elect, but were universally referred to as Emperor.
The title of Emperor (Imperator) carried with it an important role as protector of the Catholic Church, and women were ineligible to be crowned. As the papacy's power grew during the Middle Ages, Popes and emperors came into conflict over church administration. The most well-known and bitter conflict was that known as the Investiture Controversy fought during the 11th century between Henry IV and Pope Gregory VII.
Successions to the kingship were controlled by a variety of complicated factors. Elections meant the kingship of Germany was only partially hereditary, unlike the kingship of France, although sovereignty frequently remained in a dynasty until there were no more male successors. Some scholars suggest that the task of the elections was really to solve conflicts only when the dynastic rule was unclear, yet, the process meant that the prime candidate had to make concessions, by which the voters were kept on side, which were known as Wahlkapitulationen (election capitulations). The Electoral council was set at seven princes (three archbishops and four secular princes) by the Golden Bull of 1356. It remained so until 1648, when the settlement of the Thirty Years' War required the addition of a new elector to maintain the precarious balance between Protestant and Catholic factions in the Empire. Another elector was added in 1690, and the whole college was reshuffled in 1803, a mere three years before the dissolution of the Empire.
After 1438, the Kings remained in the house of Habsburg and Habsburg-Lorraine, with the brief exception of one Wittelsbach, Charles VII. In 1508, and permanently after 1556, the King no longer traveled to Rome for the crowning by the Pope.
See also: List of German monarchs. This list includes all emperors, whether or not they styled themselves Holy Roman Emperor, from Otto the Great on. There are some gaps in the tally. For example, Henry the Fowler was King of Germany but not Emperor; Emperor Henry II was numbered as his successor as German King. The Guideschi follow the numeration for the Duchy of Spoleto.
See also: Papal appointment. The Emperor was crowned in a special ceremony, traditionally performed by the Pope in Rome, using the Imperial Regalia. Without that coronation, no king, despite exercising all powers, could call himself Emperor. In 1508, Pope Julius II allowed Maximilian I to use the title of Emperor without coronation in Rome, though the title was qualified as Electus Romanorum Imperator ("elected Emperor of the Romans"). Maximilian's successors adopted the same titulature, usually when they became the sole ruler of the Holy Roman Empire. Maximilian's first successor Charles V was the last to be crowned Emperor.