Emperor (from the Roman title Imperator, meaning one with authority to command an army) is the title of an autocratic ruler of a large nation, typically one that has conquered several other nations and declared itself an empire. The feminine version of Emperor is Empress.
Occasionally, words stemming from Caesar (after Gaius Julius Caeser who was responsible for starting the Imperial Cycle in the Roman Empire) such as Tsar and Kaiser are used interchangeably with Emperor.
Emperors in Science Fiction
- Emperor (Star Wars): Ruler of the Galactic Empire
- Emperor (Warhammer 40,000): Immortal, god-like ruler of the Imperium of Man
- Charles zi Britannia, Lelouch vi Britannia, and Nunnally vi Britannia; the 98th, 99th, and 100th rulers of the Holy Britannian Empire from Code Geass
- Various members of the Goldenbaum Dynasty in Legend of the Galactic Heroes (also refered to as Kaiser)
- Centauri Emperors Turhan, Cartagia, Mollari, and Cotto in Babylon 5