The Broadway musical "Man of La Mancha" was based on which novel?

"Man of La Mancha" is a 1964 musical with a book by Dale Wasserman, lyrics by Joe Darion, and music by Mitch Leigh. It is adapted from Wasserman's non-musical 1959 teleplay "I, Don Quixote", which was in turn inspired by Miguel de Cervantes and his 17th-century masterpiece "Don Quixote". Published in two volumes, in 1605 and 1615, "Don Quixote" is considered the most influential work of literature from the Spanish Golden Age and the entire Spanish literary canon. As a founding work of modern Western literature and one of the earliest canonical novels, it regularly appears high on lists of the greatest works of fiction ever published.

The story follows the adventures of a gentleman named Mr. Alonso Quixano who reads so many chivalric romances that he loses his sanity and decides to set out to revive chivalry, undo wrongs, and bring justice to the world, under the name Don Quixote de la Mancha.

The original 1965 Broadway production ran for 2,328 performances and won five Tony Awards, including Best Musical. The musical has been revived four times on Broadway, becoming one of the most enduring works of musical theatre. The musical was performed on a single set that suggested a dungeon. All changes in location were created by alterations in the lighting, by the use of props supposedly lying around the floor of the dungeon, and by reliance on the audience's imagination. More recent productions, however, have added more scenery.