In the book, a Yankee engineer from Connecticut named Hank Morgan receives a severe blow to the head and is somehow transported in time and space to England during the reign of King Arthur.

After some initial confusion and his capture by one of Arthur's knights, Hank realizes that he is actually in the past, and he uses his knowledge to make people believe that he is a powerful magician.

Hank is disgusted by how the Barons treat the commoners and tries to implement democratic reforms, but in the end, he is unable to prevent the death of Arthur.

Twain wrote the book as a burlesque of Romantic notions of chivalry after being inspired by a dream in which he was a knight himself, severely inconvenienced by the weight and cumbersome nature of his armor.

It is a satire of feudalism and monarchy that also celebrates homespun ingenuity and democratic values while questioning the for-profit ideals of capitalism and outcomes of the Industrial Revolution.

Hank Morgan, a 19th-century resident of East Hartford, Connecticut, after a blow to the head, awakens to find himself inexplicably transported back in time to early medieval England, where he meets King Arthur.

Many passages are quoted directly from Sir Thomas Malory's Le Morte d'Arthur, a late medieval collection of Arthurian legends that constitutes one of the main sources on the myth of King Arthur and Camelot.

The story begins as a first-person narrative in Warwick Castle, where a man details his recollection of a tale told to him by an "interested stranger" who is personified as a knight through his simple language and familiarity with ancient armor.

After a brief tale of Sir Lancelot of Camelot and his role in slaying two giants from the third-person narrative, taken directly from Le Morte d'Arthur, Hank Morgan enters and is persuaded to reveal more of his story.

Upon recognizing that he has traveled back to the 6th century, Hank realizes that he is the de facto smartest person on Earth and that with his knowledge, he should soon be running things.

Hank is ridiculed at King Arthur's court for his strange appearance and dress and is sentenced by them, particularly the magician Merlin, to burn at the stake on June 21.

In prison, he sends the boy whom he christens Clarence (whose real name is Amyas le Poulet) to inform the king that he will blot out the sun if he is executed.

(Twain may have drawn inspiration for that part of the story from a historical incident in which Christopher Columbus exploited foreknowledge of a lunar eclipse.)

His assistant is Clarence, a young boy he meets at court, whom he educates, gradually lets in on most of his secrets, and eventually comes to rely on heavily.

He then undertakes an adventure with a wandering girl named the Demoiselle Alisande a la Carteloise, nicknamed "Sandy" by Hank, to save her royal "mistresses" held captive by ogres.

Hank attempts to teach the villagers about a rudimentary value theory of wages that they rebuff and in his zeal to win the argument, accidentally acknowledges that a member of his audience overpaid a worker, a capital offense.

Twain's first encounter with the Morte d'Arthur occurred in 1880, when someone in his household bought Sidney Lanier's bowdlerized edition, The Boy's King Arthur.

The pair were traveling on the lecture circuit as the "Twins of Genius" during the winter of 1884-1885 when Cable spotted the Morte on the front table of a Rochester, New York, bookstore that both were perusing.

[6] The book pokes fun at contemporary society, but the main thrust is a satire of romanticized ideas of chivalry and the idealization of the Middle Ages common in the novels of Sir Walter Scott and other 19th-century literature.

Twain had a particular dislike for Scott, blaming his kind of romanticizing of battle for the Southern states' deciding to fight the American Civil War.

[12] It is possible to see the book as an important transitional work for Twain in that earlier, sunnier passages recall the frontier humor of his tall tales such as The Celebrated Jumping Frog of Calaveras County, while the corrosive view of human behavior in the apocalyptic latter chapters is more akin to darker, later Twain works such as The Mysterious Stranger and Letters from the Earth.

George Hardy notes, "The final scenes of 'Connecticut Yankee' depict massed cavalry attempting to storm a position defended by wire and machine guns—and getting massacred, none reaching their objective.

The last chapters of the book are full of Hank's pronouncements of love, culminating in his final delirium, where "an abyss of thirteen centuries yawning between me and you!"

[2] While Connecticut Yankee is sometimes credited as the foundational work in the time travel subgenre of science fiction, Twain's novel had several important immediate predecessors.

Several works considered classics of science fiction clearly follow on this pattern set by Twain, such as L. Sprague de Camp's Lest Darkness Fall and Poul Anderson's "The Man Who Came Early".

The literary device continues to see use throughout modern science fiction, from popular American time travel stories such as Michael Crichton's Timeline to Japanese Isekai like Handyman Saitō in Another World.

Several independent films produced during the 1990s drew inspiration from the novel, such as Army of Darkness (1992) and the fourth and fifth entries in the Trancers series.

In the Carl Sagan novel Contact, the protagonist, Eleanor Arroway, is reading A Connecticut Yankee in King Arthur's Court, specifically the scene where Hank first approaches Camelot, when she finds out about her father's death.

He is introduced in the episode "Dreamcatcher" as Sir Morgan, a widower with a teenage daughter, Violet, living in a Camelot that exists in a magical reality.

In the Chronicles of the Imaginarium Geographica series by James A. Owen, Hank appears in several books as a time-traveling "Messenger" recruited by Mark Twain.