Two of my favourite fantasy stories involving knights are A Connecticut Yankee in King Arthur’s Court by Mark Twain, and Magic Kingdom for Sale! Sold! by Terry Brooks.
Both books feature protagonists in fish-out-of-water type plots.
In A Connecticut Yankee in King Arthur’s Court, Hank Morgan is the titular Connecticut Yankee, an engineer in Hartford, Connecticut, in the 19th century. After being hit on the head in a fight, Hank wakes up to find himself living in the time and vicinity of King Arthur and the Knights of the Round Table. Using his knowledge of the future (past), he then escapes being burnt at the stake by predicting a solar eclipse, and he further capitalises on his engineering know-how, to become the most powerful man in the kingdom.
In Magic Kingdom for Sale! Sold!, Ben Holiday is a lawyer in Chicago who is recovering from the death of his wife and child when he finds an improbable item in the back pages of a store catalogue.
Magic Kingdom for Sale
Landover – island of enchantment and adventure rescued from the mists of time, home of knights and knaves, of dragons and damsels, of wizards and warlocks, Magic mixes with iron, and chivalry is the code of life for the true hero. All of your fantasies become real in this kingdom from another world. Only one thread to this whole cloth is lacking – you, to rule over all as King and High Lord. Escape into your dreams, and be born again.
Could anyone resist such an offer?!
He takes the plunge only to discover that there is more to this purchase than he was led to expect.
The Landover books are a series of six titles, with possibly a seventh coming in 2021!