Romulus Augustulus
Flavius Romulus Augustus (c. AD 460 – after AD 476; possibly still alive as late as AD 507), known derisively and historiographically as Romulus Augustulus, was the Roman emperor who ruled the Western Roman Empire from 31 October 475 until 4 September 476. He is often described as the "last Western Roman emperor", though some historians consider this to be Julius Nepos. His deposition by Odoacer traditionally marks the end of the Roman Empire in the West, the end of Ancient Rome, and the beginning of the Middle Ages in Western Europe.
Holy Roman Emperor
The Emperor was crowned in a special ceremony, traditionally performed by the Pope in Rome. 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.