"One thousand years ago, King Sombra, a unicorn whose heart was as black as night, took over the Crystal Empire. He was ultimately overthrown, turned to shadow, and banished to the ice of the artic north. But not before he was able to put a curse upon the Empire."
-Princess Celestia

Everypony knows about the terror that is King Sombra and the iron-hooved grasp he had on the peaceful Crystal Empire, placing its citizens into slavery as he ruled from a palace of dark magic. That's the official story anyway. What were things like under King Sombra's reign and what really happened when Princess Celestia and Princess Luna confronted him?

*I wrote this out of boredom