Short answers, pulled from the story.
Pope Leo III crowned Charlemagne on the 25th of December in the year 800 inside St. Peter's Basilica in Rome. This coronation transformed Charles, King of the Franks and King of the Lombards, into Emperor of the Romans.
Otto I known as the Great held power starting from 962 when he became Duke of Saxony before ascending to the throne of Germany in 936. The Ottonian dynasty ended with his grandson Henry II who died without heirs in 1024.
The Golden Bull of 1356 formalized the election process under Emperor Charles IV by naming specific electors including the archbishop of Mainz, the archbishop of Trier, and the archbishop of Cologne. These seven men held exclusive voting power for centuries.
Charles V received papal coronation in Bologna in 1530 making him the final crowned emperor of the Holy Roman Empire. Ferdinand I adopted the uncrowned title in 1558 after Frederick III was the last emperor crowned by the pope in Rome on the 19th of March 1452.
Francis II abdicated his throne on the 6th of August 1806 following a devastating defeat at the Battle of Austerlitz. Napoleon Bonaparte had crushed the Austrian forces earlier that year forcing the end of the Holy Roman Empire which lasted exactly one thousand years from its traditional start under Otto I in 962.