The First Kingdom

One day, a man was relaxing on a horse ranch. There were many horses on the ranch. The horses had formed their own hierarchy, with them being led by a white horse and a horse with a blue coat. The man wasn't surprised by this unusual appearance. He knew that with the utter destruction going on around him, it was inevitable things would look weird. He had been on this ranch for so long, he was used to not seeing people, just these strange horses. His only link to the rest of the world was a newspaper he kept with a headline marked "World At War". He sadistically laughed as he noticed his own name being mentioned in the article, saying that authorities were still on the hunt for him.
He had played a large role in the war that was destroying the world. He was so smart, he decided not to become a dictator or even any kind of general in this war. He knew that all it took was for someone to get close to him to take him out. By retreating to this secluded area, he was safe and could simply play around as humanity wiped itself out. At this point, he didn't desire any sort of power, he just wanted destruction. He had contributed to the end of human civilization enough. It would be the major cities that would be destroyed first. Simply by taking them out, most of the Earth's population would be slain.

He didn't really care for being a horse rancher. He simply came there because it was as far away from civlization as he could find. He did, however, take a certain liking to one of the strange horses on the ranch. It was a black horse whose fiery spirit shown in its eyes reminded the man of himself. It was the only horse he even routinely rode. He just felt a certain bond with it. He had witnessed that this specific horse stuck out in the ground and was quite dominant, always looking for fights. He liked that in anything.

He looked up in the sky and suddenly noticed a dark shape flying overward. It was too large to be a bird, he thought. There were binoculars he kept along to keep in check of anyone coming to him in the distance. He retreated to his house and looked up. His worst fear was confirmed when he realized that it was a military plane, the kind used for bombing. He thought that maybe it was just a coincidence, that they didn't see him. All it took was one look at the bomb being dropped to realize he was wrong.

He immediately ran to his black horse. He knew that they had finally found him and wanted to punish him for the contributions he made to this worldwide atrocity. Having no idea what to do, he decided to simply ride on his horse to get as far away from the blast as possible. He was rational and knew this would barely make any difference, but decided that if he was going to die, he would at least die trying to do something.

He was fully aware of the strange explosions that had been happening around the world. New weapons were being tested all the time and they all had unforseen effects. Some were even shown to have different effects on animals than humans. In fact, the entire environment the weapons were used always changed. The specific bomb dropped on him was an experimental one that no one knew the true effects are. What better way to test this weapon than by hunting down and punishing the man who played a large part in the world war?

As the bomb hit the ground, a shockwave was released that threw the man off his horse.  You know when you are going to hit the ground and you realize something bad is going to happen for that split second before it does?  This man had a much worse as he was flying around in the air.  He knew that the best case scenario would be that he would fall somewhere and break just the fewest number of bones to not die. The worst case scenario would be if he was engulfed by the explosion, but at least then he would die painlessly fast. As luck would have it, he suffered neither of these.

The explosion ripped the skin off his bones and the eyes out of his head. He would have had even more distress could he witness the destruction of his body with those eyes. Some flesh of his tendons remained on his skeleton with a little bit of skin that hadn't come off. His head then began to go through a transition as well, with him growing ram-like horns out of his skull.

The horses were hit by the blast, but were affected in different ways. His favorite black horse grew a single horn on its head. The white and blue horses in front got the full blast and were the only horses to have both a horn and wings. The other horses formed horns and wings as well. Even those not affected had their body chemistry radically changed. They became not just stronger, but also more intelligent to the point of forming their own society. These were the first unicorns and pegasi in this new world.

One thousand years later...

A horned flying creature discovered a new kingdom.  No one else had she knew was aware of it.  It was possibly the largest kingdom in the world.  There must have been some isolation policy brought upon by the rulers to avoid outside contact.  She realized that this was the kingdom that her ancestors must have come from.  They had migrated to this land centuries ago.

The kingdom was so developed she realized that this must have been the first kingdom of its kind, the first to be established in this world.  It was created when the great war occured ages ago.  She was able to understand English as she noticed the sign said, "Welcome To Equestria" but spoke Korean as most rainicorns.