From 'The Collected Histories Of Clara Terram'.
Three centuries after the founding of Clara Terram, and two centuries after the discovery of magic, an unexpected event occurred, one that would have repercussions that would be felt even to the modern age. That event was the birth of the king's second son, Madigrin.
Clovis, the firstborn, was strong, brave, ruggedly handsome, wise, honest, kind, generous, and charismatic. He was well beloved by the citizens of Clara Terram, and his coronation was looked forward to all, save one. While not blessed with any talent with magic, let alone magic energy, he would, in years to come, prove himself to be an able administrator, and would usher in a golden age for our people. The second son, Madigrin, however, was different. Rather than handsome, he instead possessed an almost effeminate beauty. He was clever, and possessed a certain magnetism that seemed to draw others to him, in spite of his personality. He was also deceptive, calculating, and cruel to the point of sadism. He also possessed, most importantly, tremendous magical power, the kind that few in our history have matched.
And this was where the trouble began.
"Why should I serve others?" Madigrin asked of his father. "Why should I serve my brother, who has less magical capability than a stone? With a word, I can tear down mountains. With a wave of my hoof, I can bring fire and ruin to any who might threaten our kingdom. With a thought, I can rend even the strongest of warriors asunder. Why shouldn't I be the king instead of Clovis?"
While upset by his words, the king advised his younger son that magic alone did not make one worthy of ruling a nation. His incredible talent had left him lacking in humility, unlike Clovis. The king could trust Clovis to rule the kingdom wisely and well because he knew that he was only a mortal pony. Madigrin, however, would not, since he thought his magical abilities made him some sort of god, something that none of the ponies of Clara Terram would stand for.
"Had our ancestors not left the homelands specifically to escape the sort of tyranny you intend? To escape the horned and the winged ones who treated them as nothing more than slaves? Those who forced us to pay tribute to them and thought themselves superior to us in every way? The people will not stand for a pony who tries to rule over them using abilities that they do not possess. If you become king, our subjects will either revolt and overthrow you, or abandon our kingdom, leaving you all alone to rule over an empty nation. No, my son: You are not fit to rule, and I fear you never will be..."
Madigrin would not take no for an answer. He instead would pour venomous, honeyed words of treason into the ears of those members of the populace who possessed great magical power, yet felt constrained by the traditions and laws of our people. He promised them power, the ability to rule over others. They would be as gods, and Madigrin, the king of gods. Within a year, he had a sufficient following to try to seize the throne.
The coup failed, ultimately, due to Madigrin's own twisted dogma, his belief that only magic mattered, and that anypony without magic was beneath contempt. Moons before his coup began, an unspelled serving girl had overheard a conversation between Madigrin and his cohorts while serving them drinks. He thought nothing of speaking treason before a magicless commoner. This would be his undoing. The maiden reported the plot to the newly crowned king, and the king made preparations of his own. When the coup began, Madigrin and his flunkies found themselves faced, not with a palace of unprepared courtiers and servants, but with knights of the realm armed with anti-magic arms and armor, and dozens of powerful wizards who were loyal to the king and to their people. The coup was stopped without a single casualty, and both Madigrin and his followers were captured and brought before the king for judgement.
And on that day, the king made the one mistake of his reign, the mistake that haunts us to this very day: He chose mercy, rather than justice.
The penalty for treason was death. This had always been the case. However, when Clovis looked upon Madigrin, he could only see his brother, and not the monster he was, and certainly not the twisted thing he would eventually become. Instead of death, the king chose to exile his brother. Although, in fairness, the destination of his exile was practically a death sentence.
The Dark Lands were a large island off our eastern shore, the site of a magical battle between two powerful wizards a century previous. Then, as with now, nothing existed there that was not lethally venomous, violently carnivorous, psychotically aggressive, or a combination of all three. That included even the plants, many of the stones, and some of the lakes and rivers. It was expected that Madigrin would die there, as would his followers.
That expectation was not completely wrong. However, it was not right, either...
A century later, the first attack from the Dark Lands, The Day Of Infamy, began. And we have not known peace since then.
Fear of an attack from Madgrin colors every aspect of our civilization: None dare try to leave our kingdom to explore for fear of a repeat of what last happened when Madigrin captured a ship filled with hopeful explorers. Our blue skies have been tinted by the defensive barriers that protect us from his continuous magical onslaughts. Even the taste of our water has been subtly altered due to the dozens of antigens, antitoxins, and alchemical elixirs required to prevent Madigrin's dark magics from introducing plagues or worse into our water supply and do harm to our population.
There cannot be peace between Clara Terram and the Dark Lands. Not so long as Madigrin sits upon its throne. Any who have attempted to broker peace with him have been slain, and their deaths were long, protracted, and broadcasted nationwide for every pony to see. Whatever good was within Madigrin died when he did, and the abomination that he has become is now our adversary, now and forever. He will possess our nation, even if he must burn it all to ash to do so. He will become king by any means necessary, even if it means he will be a king of only the dead...