A long time ago, above and beyond the land of Equestria and the world on which it sits, four spirits sprang up into existence that would govern the mortals below by controlling the four great powers. Chaos, Order, Life, and Death. Two pairs of beings to create their power, spread it across the world, and maintain balance with the one who controlled their opposite.
Of these four beings, Discord and Harmony – Chaos and Order – were the eldest. Although they were meant to be as brother and sister, the two siblings could not keep a rivalry between them from forming. The maintaining of balance between them grew to feel more of a burden to them both. Discord did not want to keep his power over chaos under control, finding it amusing to watch the effect his prolonged influence had on the ponies. In contrast, Harmony grew to love the ponies over which they watched, and it hurt her to see them be tortured by her partner.
Though both beings had different dreams when it came to the world they observed, they did share one thing in common. Both Harmony and Discord cherished secretly a dream to live among the mortals. Harmony wished to live with the ponies to help them, guide them, and love them more closely. Discord only saw the ponies as a means for more interesting and creative ways of chaos. Yet their fascination for the mortals was so great that the two even formed corporeal bodies to better mimic what they saw.
Harmony selected the best qualities of all three species of pony, and became the first alicorn. Discord – to emphasize his intrest in spreading his power through all the species of Equus – chose an assortment of attributes for his body. He became the first (and so far only) Draconequus.
Long the two stayed in their high above realm, both siblings keeping the other from achieving their true shared dream. Harmony feared how her influence in the world might affect the ponies she loved so dearly, and she greatly feared what would happen should Discord be allowed to live freely there.
Discord stayed above solely because of his sister. For in those days it was not yet known by any of them the consequences for leaving one’s partner for another world.
Ages past, and new lands grew on the world below them, and soon the two had aged far longer than a spirit can when inhabiting a body. Maintaining a form permanently can deplete them, age them from the inside even if their outward appearance stays the same.
It became too much for Harmony. She did not want to leave the world she loved so without the power that she controlled. She saw this as her chance to find a way to touch the mortal world in an even more real way, to show her ponies her love for them. So out of her love for them, she pulled her force of Order from herself, and combined it with that love. Her love was such that she was able to create not one – but two brand new beings from it. These were her daughters, Celestia and Luna. The second and third alicorns.
They were created to take her place in the balance, and specifically to be allowed to take the place among the mortal ponies that Harmony had longed for for an eternity.
Sadly, creating her successors had drained Harmony so that she could no longer stay in a corporeal form, and – no longer needed to keep the Order – she faded away.
Without his sister for the first time in his life, Discord was free to at last do what he had always dreamed. He found a way down to the world of the mortal ponies, and exacted his chaos upon them, taking them over and ruling them with an absurd ease. His new partners in balance – the daughters of Harmony – may have been young, but were still understanding of their roles in this world, and they shared their mother’s love for the world Discord was harming.
The two young alicorns tried to reason with Discord, but he would not listen. His power in this world was even more chaotic and destructive than he could have ever imagined. No longer confined to only spreading an equal amount of his power to his sister’s, Discord quickly ravaged the land and the bonds of the ponies nearly without even trying.
He also quickly grew bored of it. Something that which is without an equal – without a challenge – can not satisfy even a spirit of chaos forever. He grew lonely, although he had never known the feeling before and therefore could not name it.
The alicorns meanwhile discovered a secret weapon forged by Harmony on the off chance her brother could ever get away from her. The Elements of Harmony were created from the six elements that made up the best qualities in the beings she loved so. Her daughters found them, and used them to bind their uncle in what they hoped was an eternal prison.
Discord was turned to stone, but not returned to the plane from which he had come. The two keepers of Order still needed him to maintain his part of the balance, but they could not trust him to keep himself restrained to their equal level of power, especially from a place where they could not watch him.
So they left him in stone, from which the draconequus would still exude his power, but on a level that was always maintained and steady. Steady enough for the sisters to keep things equal for their world.
There Discord stayed until the sisters and newly made princesses of a new land called Equestria passed on the elements they bore to keep him confined to six new keepers.
Only the eldest daughter of Harmony knew that one among the six new bearers had been chosen to take on the position as keeper of Order as well, for she had selected that pony herself. Neither the Order nor the Chaos keepers however could have imagined the alterations that would be made to interrupt this destiny. Because the mind and heart of a mortal pony was something even more unpredictable than either of their powers.