Long ago, before the discovery of Equestria...
Before there was a Unicorn, Pegasus, or Earth Pony; Alicorns once roamed the lands of the world, living in peace and tranquility. All ruled by the kind, just, and beautiful Queen Harmony. Her and her Counsel of Five assured all their subjects would lived under their virtues: Honesty, Kindness, Laughter, Generosity, and Loyalty. All had lived in peace, but not for long. For Queen Harmony's wicked sister, Armageddon did not believe in such cheerful gestures. She would plunge the everything into total blackness, and rule it to her liking. It was then that a battle was thrown between the two sisters. The Counsel of Five aid the queen with all their might. They would struggle until they nearly destroyed each other and the world around them. But when it was all over, the Alicorn race had simply vanished, and the two sisters and counsel along with them.
But in their place, the three pony tribes were suddenly born: Earth Pony, Unicorn, and Pegasus. With no memories of how or why they were there, they taught themselves to have purpose. But the Queen didn't leave these new ponies with nothing. Before she disappeared, she left behind the Tree of Harmony. But most importantly, she left behind two fillies, two alicorns, two daughters...Princess Celestia and Princess Luna.