Holy Roman Empire
The empire was dissolved on 6 August 1806, when the last Holy Roman Emperor Francis II (from 1804, Emperor Francis I of Austria) abdicated, following a military defeat by the French under Napoleon at Austerlitz (see Treaty of Pressburg). Napoleon reorganized much of the Empire into the Confederation of the Rhine, a French satellite. Francis' House of Habsburg-Lorraine survived the demise of the empire, continuing to reign as Emperors of Austria and Kings of Hungary until the Habsburg empire's final dissolution in 1918 in the aftermath of World War I.
Holy Roman Emperor
While earlier Germanic and Italian monarchs had been crowned as Roman Emperors, the actual Holy Roman Empire is usually considered to have begun with the crowning of the Saxon king Otto I. It was officially an elective position, though at times it ran in families, notably the four generations of the Salian dynasty in the 11th century. From the end of the Salian dynasty through the middle 15th century, the Emperors drew from many different German dynasties, and it was rare for the throne to pass from father to son. That changed with the ascension of the Austrian House of Habsburg, as an unbroken line of Habsburgs would hold the Imperial throne until the 18th century, later a cadet branch known as the House of Habsburg-Lorraine would likewise pass it from father to son until the abolition of the Empire in 1806. Notably, the Habsburgs also dispensed with the requirement that emperors be crowned by the pope before exercising their office. Starting with Ferdinand I, all successive Emperors forwent the traditional coronation.