"When we, in our bitterness, became Nightmare Moon and rebelled, we did not do so alone. Though most ponies shunned the moon, a few joined in our reverence for the night, and secretly preached our creed, growing in  number until they were a force to be reckoned with. It was then that we  struck, and they, calling themselves the League of Stars, followed us  into rebellion and sedition. While we sought to wrest power from our  sister through magic, they marched on the Castle of the Two Sisters,  besieging its defenders."