Prologue
In the world of Equestria, across the wide ocean from the continent Equestria itself, lies the land of Aquilonia. It is a hard land, ruled over by the Alicorn Prince Aligorna. It is a rocky land, mountainous, with only a few unicorns and no pegasi to generate weather, meaning that most of its weather is the remnants of that created in Cloudsdale in the weather factory that drifts from Equestria across the sea. As such, growing food for the earth ponies that make the majority of the population is a struggle. What they have at their disposal though is the sea itself, which Prince Aligorna's magic has power over. The ponies of Aqulonia have long been known for their skills as fisherponies...and as pirates.
Soon after the defeat of Discord, over 1000 years ago, Prince Aligorna traveled to Equestria to meet the triumphant sisters, hoping to cement an alliance with them. He spent a week there, conducting business with Princess Celestia but spending most of his private time with her younger, dark maned sister Luna. He would sit and watch her in her work at raising the moon at night, and listen to her sing and dance to the night. An arrogant leader who believed the Alicorns to be gods, and understanding that Luna's moon was the driving mechanism behind his tides, he became convinced that it was divine right that they were meant for each other. He never got his chance to court her though. Soon enough, his treaty with the sisters was negotiated and he sailed back to his homeland, agreeing that he would meet the sisters every once in a while to work out new treaties to benefit both parties and even to reduce or eliminate his people's piracy. He hoped that in those times he would be able to pursue the young Luna, but after a few short years, he received the news. Jealous that Equestria's ponies slept through her beautiful night while enjoying her sister's sunny days, Luna had transformed herself into the villainous Nightmare Moon and had been banished into the moon by her sister.
Prince Aligorna was extremely dejected. He had missed his opportunity, and in the process lost what he was so sure was his divinely chosen mate. He and Celestia ruled their respective lands peacefully for 1000 years, maintaining a friendly working relationship the whole time. Then something miraculous happened. Luna started appearing to him in dream, singing and dancing for him, beckoning him back to Equestria. Word soon reached him that one of Celestia's students, Twilight Sparkle, had gathered a group of friends together and used the mystical weapons known as the Elements of Harmony to defeat a returned Nightmare Moon and bring her back to her benevolent form of Princess Luna. Convinced this was a sign, he started to gather a crew and sent word to Celestia that he would be meeting her again soon. It took over a year to complete preparations, but in that time he grew more and more content with this being his opportunity, largely in part to his newly acquired vizier.
This vizier was new to his position, but he was not new to the ponies of Aquilonia. He was Strife. The ponies of Equestria had always assumed that Discord was the only draconequus (dragon pony, the technical name for the chimera-like conglomerate of species that make up their being). This was false. In fact, he had a brother, operating across the sea. But unlike Discord, Strife didn't oppose the people he lived amongst, but made an alliance with Aligorna early on, becoming the Aquilonian's battle god, their protector and benefactor during raids. When the piracy stopped, he had stayed on as one of Aligorna's advisers, and now was whispering in his ear the plan that Aligorna hoped would win Luna's heart.