Equestria was created by Night Eyes and Wildfire. From darkness came the light of the kingdom. But the Two knew that Equestria could not exist with out darkness. So they created Him.

Many eons past since the first day. Night Eyes had two little fillies, Celestia and Luna(honestly, did I really have to tell you their names? ). It was a happy time for the kingdom, and everypony celebrated. But the Darkness was to come forth for his turn to rule. Night Eyes and Wildfire knew that. And so was the greatest tragedy of Equestria yet to come.

Author's Note:
Despite the cover art, this has very little (if not nothing) to do with King Sombra.