Emperor

An Emperor is the highest authoritative title associated with the ruler of an Empire. Its also a type of penguin. In common usage, an Emperor is a person of the male gender. A female who assumes this role is referred to as an Empress.

In the Star Wars film series, the former Chancellor of the Republic, Palpatine, declared himself Emperor when he restructured the Republic into the First Galactic Empire at the end of the Clone Wars in 19 BBY. He's been pretty much an a-hole ever since. When Palpatine finally died in 4 ABY, the Empire dissolved and was replaced with a new government.