Early modern period
In the early modern period, the Holy Roman Empire was a union of territories in Central Europe under a Holy Roman Emperor the first of which was Otto I. The last was Francis II, who abdicated and dissolved the Empire in 1806 during the Napoleonic Wars. Despite its name, for much of its history the Empire did not include Rome within its borders.
Holy Roman Empire
After Charlemagne died in 814, the imperial crown passed to his son, Louis the Pious. Upon Louis' death in 840, it passed to his son Lothair, who had been his co-ruler. By this point the territory of Charlemagne had been divided into several territories, and over the course of the later ninth century the title of Emperor was disputed by the Carolingian rulers of Western Francia and Eastern Francia, with first the western king (Charles the Bald) and then the eastern (Charles the Fat), who briefly reunited the Empire, attaining the prize. After the death of Charles the Fat in 888, however, the Carolingian Empire broke apart, and was never restored. 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.