The Son of the Emperor

""Behind or under every great man, there is a great pony.""

The year is 1820, Napoleon has been defeated and exiled, Europe is slowly returning to it's old and tried ways. But unbeknowst to anyone a series of events bring together a young unicorn and a human prince. Together they will change Europe, and the world, forever.

This is the basis of The Son of the Emperor, a Alternate Universe/Alternate History My Little Pony: Friendship is Magic Fanfic written by NoMoreSanity and set on 19th century Earth, where Equestria and ponies exist alongside humans.

It follows the friendship between Twilight Sparkle and Charles and the effect it will have on world history, while at the same time speculating on how the world would look like if sentient talking ponies, griffons, dragons and magic were a common occurance.

Can be found here, here and here.

This fanfic provides examples of:

 * A Prince And His Unicorn
 * Alternate Universe: Ponies grow to the size of real world horses and have been used for work and in war for centuries. Apart from that the world is also inhabited by dragons, griffons and other mythological creatures. Equestria takes up a large chunk of the modern United States' west coast (and parts of Canada and Mexico) and is the most isolated country in the world thanks to its magical barrier.
 * Alternate History: Although at first it seems like history is the same as in our world, there are indications that this is not the case and that the history of the world is different from our own. This also seems to be the case with Equestria and it's history in contrast to the cartoon.
 * Ban On Magic: Unicorn magic has long been a controversial subject, with some wanting limitations to be put on what spells unicorns can learn or even calling for banning the use of any form of magic . Evenutally powerful spells were banned and all books and knowledge on them destroyed. The result of all this is that unicorns outside of Equestria are very limited in their abilites (save for a few capable hermits who have eluded capture).
 * Call a Rabbit A Smeerp: Even though ponies grow to the size of horses, they are still called ponies. Word of God states that the reader should just roll with it.
 * According to one reader's comment, real world horses and ponies tend to vary so much in size and shape that the story's use of the word pony isn't really that big of a problem.
 * Can't Hold Her liquor: Twilight, apparently. See the Noodle Incident entry for more. However according to Antonie, most ponies tend to be of the Never Gets Drunk disposition.
 * Cool Horse: Twilight Sparkle
 * Crack Fic: A crossover of My Little Pony with...nineteenth-century European historical politics?
 * Cute Shotaro Boy: Charles himself.
 * Deadly Decadent Court: How Charles sees the nobility around him.
 * Disappeared Dad: Twilight's dad is missing and she doesn't know what happened to him. And of course, Charles.
 * Gratuitous Foreign Language: French and German words are mixed in with English dialogue to convey the fact that the characters are speaking in a foreign language and not English.
 * Epigraph: Each chapter starts with a quote, mostly from historical figures.
 * I Thought Everyone Could Do That: Twilight is surprised by the fact that something as mundane as lifting books or opening a door with magic is unheard of outside of Equestria. This is because unicorns are not allowed to practice magic beyond certain strict limits, and most of them can't perform even the most basic tasks.
 * Hidden Elf Village: Equestria has no contact with outside world and nobody knows anything about it. A magical barrier at its borders allows people to enter, but no one has ever left.
 * Historical in Joke: It is still debated whether Caligula was a hero or a madman for entrusting the position of Consul to his most trusted pony.
 * One character is named and based on a real person, the only difference is that here he's a pony.
 * Hold Your Hippogriffs: Crops up from time to time. This being an MLP fanfic, it comes with the territory.
 * Kidanova: Charles lost his virginity to  at the tender age of 13.
 * Muggles: Humans in contrast to unicorns posses no magical abilites.
 * Noodle Incident: Twilight's 15th birthday, where she had her first taste of alcohol. Whatever took place was so bad that she had to take an oath to never speak of it again.
 * No Just No Reaction: Happens to both Charles and Twilight when Antonie makes a joke about humans and ponies being together.
 * Only Friend: Twilight seems to be this for Charles.
 * Parental Substitute: Charles sees Antonie as this, but is ashamed to admit it.
 * Physical God: Celestia and Luna are probably this. Celestia herself is also worshiped by the Aztecs, and Celestian and Lunanite religions exist.
 * Sapient Steed: Ponies are intelligent beings that can easily communicate with humans; some even hold positions in the military, or are nobles.
 * Shown His Work: The author pays a lot of attention to historic details, and it shows.
 * Super Human Trafficking: Twilight meets Charles after she escapes from a pony slave caravan, but it's later revealed that pony slavery is strictly illegal in Europe.
 * Tell Me About My Father: Charles is very persistent in asking Antoine questions about his father. Antoine eventually decides to tell him.
 * Unreliable Expositor: The history books Twilight and Charles have read tend to be either biased or unable to get accurate information. Especially when dealing with topics such as Equestria.
 * X Meets Y: Post-Napoleonic Wars-Europe meets My Little Pony.
 * Your Cheating Heart: Sophie, seeing as she slept with  while she was engaged to Archduke Franz Karl.