Long ago, in a time when kings and queens still ruled Equestria, ponykind was confronted with a relentless foe unlike any they had faced before. The creatures were strange, twisted amalgamations. Their bodies were covered with scales and fur, with the limbs of lions and bears, and vicious claws.
They called themselves “Draconequus.” Wielding powerful Chaotic magic, they sought to conquer the peaceable races of ponykind, devastating vast swaths of Equestria as they waged war.
Ultimately, the ponies drove the Draconequus back. But they paid dearly for their victory.
As vast swaths of Equestria were subdued by Chaos, the Draconequus pressed ever closer to the heart of the kingdom. The king and queen of ponykind at that time hatched a daring plan: they would give up their lives to form the Alicorn Aspects and the Elements of Harmony. They believed that these magic artifacts would be able to turn the tide of war in their absence.
Instructions were left to bestow the Aspects on those that were honorable and pure of heart, that they might serve as princes and princesses in their stead. Likewise, the Elements were empowered to bestow unique abilities upon noble bands of ponies for the defense of Equestria. At the Alicorns’ discretion, ponies would be allowed to take up the Element which resonated with their heart of hearts.
Leaderless, the ponies turned to Princess Celestia and Princess Luna, daughters of the king and queen. They took up the first Alicorn Aspects, infused with Order. The sisters then bestowed the Elements upon six of their closest and most trusted friends. With their power combined they were able to drive back the Draconequus and restore peace and tranquility to Equestria.
The ponies mourned their king and queen but rejoiced over their victory. The Age of the Princesses was renowned as a time of bliss and plenty. Due to their seemingly endless reservoirs of Order, the Alicorn Aspects granted such long life as to make the princesses’ nigh immortal. The bearers of the Elements of Harmony aged as normal, given great power but no extension of life. Many generations of ponies came and went, with Celestia and Luna selecting new Elements of Harmony from the ponies with the greatest potential in each.
Then Luna was corrupted by the Nightmare and became Nightmare Moon, a being of incredible power that grafted Chaos together with the Order of her Aspect.
Fearing the strength of her sister in the embrace of the Nightmare, Celestia was forced to use a powerful spell to banish her far above the green fields and mountains of Equestria on the moon. For a thousand years, Luna grappled alone with the Nightmare force that grasped at the source of her power. But she fought it to a stalemate and the Nightmare waited, biding its time—as an ancient evil must learn to do.
For it too knew the nature of the spell that Celestia cast. That a prophecy foretold the banished would return after a thousand years. It knew that it would be given another opportunity to obtain more Alicorn Aspects and grow its own power.
When the spell ended, Nightmare Moon found herself confronted by the six strongest Elements of Harmony that had ever been. And leading them was Twilight Sparkle, a magic user that far surpassed other Unicorns, rivaling even the Princesses’ in their prime.
Twilight and the other Elements subdued Nightmare Moon, restoring Luna to her right mind and casting the Nightmare away into one of the world's darkest corners. Into Tartarus, where it waited and brooded once more.
Centuries before Twilight and her friends took up the Elements of Harmony; before the combined forces of Chaos rampaged across Equestria, driving the ponies into exile; while Nightmare Moon still paced the lifeless dunes of the lunar surface; the sages of zebrakind portended that Chaos would return after its defeat. They spoke of another world, its fate entwined with that of Equestria. That one would rise—a hero destined to save both worlds from the greatest threat they had ever known…
But in so doing, it would cost him his life.
*****
The future’s dark, that much is true
But a mote of Light I bring to you
When the wrath returns; the evil ones
And Chaos reigns beneath the sun
Two worlds to fall, but One to rise
And made to shine in dark of night
He bears our burden, both in kind
The Golden One to guard his mind
To save, he must like stars to fall
And wake the Hopes and Dreams of all
-Chieftan Tan’eruk of the Southern Zebra Tribe, Year 226 After Luna’s Banishment