A Connecticut Yankee in King Arthur's Court

A Connecticut Yankee in King Arthur's Court is a classic 1889 novel written by Mark Twain, about, well, exactly that. Hank Morgan, a resident of Hartford, Connecticut, suffers a blow to the head and inexplicably awakens to find himself in sixth century Britain. There, he is able to convince King Arthur that he is a powerful wizard and ends up assuming the job of the king's adviser, and attempts to impose modern technology and values onto the society.

The novel is both a satire and a seminal work of time travel science fiction. The story has been adapted many times for film, television, and other forms of media. Surprisingly enough, given the book's popularity, most literary critics rank Connecticut Yankee among the worst of Twain's written works.

It's in public domain; the full text can be downloaded for free at Project Gutenberg.

This Work Contains Examples Of:

 * Ax Crazy: Morgan Le Fay. Literally.
 * Badass Nickname: Hank Morgan's title is "The Boss"
 * Big Damn Heroes:
 * Butt Monkey: Merlin, the ultimate exemplar of human ignorance and superstition, a con man who believes his own con.
 * Brick Joke: "Hello, Central."
 * Clarke's Third Law: Hank uses this to his advantage, performing many "miracles" with his knowledge of science and engineering.
 * Combat Pragmatist: Hank, but also the knights -- Hank notes when he's charged by three knights simultaneously that there's none of this chivalrous one-against-one stuff.
 * Conservation of Ninjutsu:
 * 52 boys with modern 19th-century technology vs. 30,000 knights. Guess who wins...
 * Earlier in the story, Hank takes on 500 knights with just a pair of revolvers  To clarify,
 * Convenient Eclipse: one of the most iconic examples and probably the place where this trope is usually drawn from. Hank is about to be burned at the stake when an eclipse happens, convincing the locals that he really is a powerful magician. They promptly set him free according to his demands. In a tragic inside reference for Mark Twain, Hank is sentenced to be burned at the stake on June 21. Mark Twain's brother Henry was fatally burned in a fire on a steamboat, and succumbed to his injuries on June 21. Twain's biographer Ron Powers argues that this was Twain's way of dealing with his brother's death: allowing his Expy to survive death by burning.
 * Corrupt Church: Hank views the Roman Catholic Church this way and he is proven right when
 * Crapsack World
 * Curb Stomp Battle: Medieval knights can't compete with 19th century military technology...
 * Deconstruction: of Arthurian legends.
 * Disproportionate Retribution: Morgan le Fay stabs a servant for bumping her, and has a man thrown into the dungeon (with a view of his own home, where she stages fake funerals to make him think that all but one of his family have died so he'll torment himself trying to guess who the Sole Survivor is) for saying her hair is red (it's actually auburn). And in the Hypocritical Humor typical of the protagonist, Hank Morgan hangs bad musicians and knights who tell jokes that have passed their use-by date.
 * Downer Ending:
 * Emperor Scientist: Since "The Boss" leaves Arthur and his court in charge as harmless figureheads and relies more on inventions than science, he's more of a Shogun Engineer.
 * Evil Sorcerer: Averted. Merlin isn't really evil, he's just a Jerkass.
 * Fish Out of Temporal Water
 * Gatling Good
 * Gentleman Snarker: Hank is this way with almost everyone, but especially the nobility. It usually goes right over their heads.
 * Giving Radio to The Romans: Hank gives many modern devices such as the telephone to medieval Britain, although most of them don't seem to be able to grasp the concept of how these things actually work.
 * God Guise: A late 19th-century American is sent back in time to the Dark Ages and becomes an important member of King Arthur's court, using his advanced scientific and political knowledge to greatly improve the quality of life of the kingdom, while also discrediting Merlin (revealed to be a fraud) with his own advanced technology and intelligence that makes him look like a true Sorcerer. In the end,
 * God Test: Done memorably when a charlatan claims to be able to tell people whatever is happening anywhere in the world. After listening to various plausible tales of the doings of foreign potentates, Hank takes his turn: "Tell me what I'm doing with my hands behind my back right now."
 * Guns Akimbo: Hank with his Colt Dragoons during his duel with the knights.
 * Handwaved: There's no explanation for how Hank got to Camelot in the first place. Similarly,  are also never addressed. There's a reference to "transmigration of souls" but that doesn't explain how Hank's body (and clothes) change centuries either.
 * Hand Cannon: It's interesting that no-one refers to Hank's revolvers as this. However, the Colt Dragoon was one of the most powerful handguns of its day.
 * Humans Are Bastards: The thesis of the book seems to be that it's not the time period, the society, or the level of technology and infrastructure that make people do evil things, it's just basic human nature. This being a Twain book, however, there a few stubborn kernels of optimism that refuse to be stamped out in the book. Whether this is a straight example of this trope or a subversion depends on the reader's interpretation.
 * Incredibly Lame Pun: On first meeting Clarence the page, Hank comments that he's no more than a paragraph.
 * Jerkass: Medieval society is arranged to specifically encourage and reward this sort of behavior on the part of the nobility and clergy. It is, in effect, the Empire of the Jerkass.
 * King Arthur
 * King Incognito: Arthur does this at one point while journeying with Hank, who wants to show him first hand what life is like for his people.
 * Knight Errant: Hank reluctantly becomes one, and the knights of the round table also qualify.
 * Lawful Stupid: The denizens of Camelot always put the rules before good sense or basic human compassion.
 * The Munchausen: All the Knights of the Round Table -- no-one ever questions another knights' tale of adventure, no matter how ridiculous.
 * Medieval Morons: At least, in Hank's eyes. There's also that situation with Sandy and the pigs...
 * Mood Whiplash: The story starts as an amusing fish-out-of-water story and a satire of Arthurian legend, but by the end it's a rather grim lampoon of modern England and America that saddles us with a real downer ending.
 * More Dakka: The final charge of the knights vs. Gatling guns.
 * Never Bring A Sword to A Gunfight:
 * No Endor Holocaust: Averted. After the final battle in which tens of thousands of knights are killed, Morgan's hand-picked band start getting ill from all the decomposing bodies.
 * Princess Classic: Also deconstructed, as the ladies of the time are as rude as anyone else.
 * Real After All: After being systematically defeated and shown to be a fraud for the entire book,
 * Reality Subtext: Mark Twain's life was seriously affected by family death at the time. Twain was in a "Rage Against the Heavens" mode.
 * The Resenter: Merlin, after Hank out-magics him.
 * Revolvers Are Just Better: Justified, Revolvers where the only handguns in Hank's native time and Hank is the only gunslinger in a world full of sword-wielding knights.
 * Ridiculous Future Inflation: In anticipation of which, medieval Britain's new decimal currency is the cent, composed of 100 milrays.
 * Snipe Hunt: Averted. Everyone but the Yankee actually expects the harebrained quest they send him on to turn out to be genuine.
 * Spanner in The Works: Discussed. "The best swordsman in the world doesn't need to fear the second best swordsman in the world; no, the person for him to be afraid of is some ignorant antagonist who has never had a sword in his hand before; he doesn't know the thing he ought to do, and so the expert isn't prepared for him."
 * Stable Time Loop: Though averted in one animated adaptation -- The hero wakes up in the present-day hospital and immediately goes to an encyclopedia to look up King Arthur...and bursts out laughing when he finds a picture of the king straddling a motorcycle.
 * Stranded With Edison: Hank is impressively knowledgable about the details of 19th-century technology, even leaving aside the part where he's apparently memorized a 6th-century almanac.
 * Tear Jerker: Frequently, particularly when the Yankee takes the King out incognito to see what peasant life is really like.
 * Talkative Loon: Sandy, though Hank realises she's not actually crazy; she just lives in a world where people seriously believe that enchantments can turn princesses into pigs. Although she goes on and on driving him to distraction, Hank starts warming to Sandy once her quick talking gets him out of a sticky situation.
 * This Is My Boomstick: Hank manages to be quite impressive with a few homemade explosives.
 * Timeline-Altering MacGuffin: The inventor himself.
 * Time Travel
 * Trapped in The Past: Hank Morgan
 * Values Dissonance/Deliberate Values Dissonance: In-Universe,between the Yankee and the Arthurian Britons. The reader may also feel some disassociation from the Yankee's worldview, which is probably intentional.