Under going a rewrite.

On June 5th, 1057 of the 4th era, an Aurora Borealis forms above the night sky of Canterlot. On that fateful night, The Royal Pony Sisters find a dying human woman with a baby boy in the castle gardens. After they make promise to look after her only child, she passes away, and the Princesses adopt him as their own son. The Princesses will grow love him in the coming years, but they will find that raising him will be the least of their worry's for a storm in the East grows with each passing year.

Story: Made by me.
Editor: Pandora.
Cover Art: Made by SapsDrow, here's his deviantart page.