Holy Roman Emperor

The Holy Roman Emperor was the ruler of the Holy Roman Empire.

In 800, Pope Leo III crowned Charlemagne as emperor. (PROSE: The Lonely Computer)

Maximilian I was the Holy Roman Emperor in 1504. (AUDIO: The Ghosts of N-Space)

In an alternate timeline in which all of history occurred at once, Winston Churchill was the Holy Roman Emperor. (TV: The Wedding of River Song)