The history of Princess Celestia and Princess Luna is somewhat a mystery. We know little about their dark past, so why not shed some light on the topic?

Nopony really knows where Princess Celestia, Princess Luna, the Changeling Queen or Discord came from. But they do. Told from Luna's point of view, she tells the story of how she became a leader, a princess, a victim of love, a prisoner and guardian of the night.

Princess Celestia was the creator of Discord. She decides to make a revised version of him, but she had no idea that this one would be a girl! Eris is her name, and as Celestia teaches her the ways of life, Discord breaks free from his prison for the third time. Upon meeting Eris, his plans to take over the world take a back seat...
(credit to jaqueline amy rose, creator if Eris)