Culture of ancient Rome
The Roman Empire, at its height (c. 117 CE), was the most extensive political and social structure in western civilization. By 285 CE the empire had grown too vast to be ruled from the central government at Rome and so was divided by Emperor Diocletian into a Western and an Eastern Empire. The Roman Empire began when Augustus Caesar became the first emperor of Rome (31 BCE) and ended, in the west, when the last Roman emperor, Romulus Augustulus, was deposed by the Germanic King Odoacer (476 CE). In the east, it continued as the Byzantine Empire until the death of Constantine XI and the fall of Constantinople to the Ottoman Turks in 1453 CE. The influence of the Roman Empire on western civilization was profound in its lasting contributions to virtually every aspect of western culture.
Holy Roman Emperor
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, the coronation of Charles V. 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.