…long before the age of Equestria;
there was a great pony god, La'uriel, who was responsible for the current cycle of Creation, along with the rest of the Cosmic Council.
Therefore, she created ponykind, a free-spirited and docile race of equines, to roam freely in this new world.
But the Cosmic Council betrayed her, and enslaved the ponies for their own purposes.
The pony god stood up to the Council, but for her insolence, they banished her to the earth, and cursed her, so she could never interact with her creations again. She was struck by grief that she couldn't help her little ponies, and wept for them, her tears striking the very ground.
In a last ditch effort to help, and to circumvent the curse placed upon her, she gave up all her power, and created twelve immensely powerful beings, to her own image, who would guard ponykind in her stead.
These beings were the alicorns.
With that, La'uriel passed, and her soul moved on to Caelum, the realm of magic.
The alicorns sought out ponykind, and bestowed part of their magic upon them. One group of ponies wanted to interact with the arcane at will. Another wanted to soar freely among the clouds. While the third group wanted to harness the gifts of the earth with no effort.
The alicorns granted them the desired powers, and therefore, the three tribes of ponies came to be. But now being so different, they separated, and went on to live in their own ways, in different parts of the world.
The alicorns, this way freeing ponykind from the clutches of the Cosmic Council, retreated to an island in the ocean, staying vigilant, ready to help if need be.
Eons passed. The alicorns, who grew to a small tribe in the meantime, helped ponykind many times, when it was most necessary.
But times have changed. The oldest members of the ancient tribe slowly grew tired of their role as mere guardians. They sought more. They wanted to be more. They cared less and less about ponykind's safety.
Conflict flared up between members of the tribe, as many wanted to remain at their roles as guardians, against those who did not.
Into these turbulent times, a new alicorn was born. And soon, her sister as well. And unbeknownst to them, they would go on to help shape the fate of their tribe, ponykind, and the whole world as well...