Despite portraying Falstaff as a grossly obese man, Orson Welles actually had to diet to slim down for the role.
This movie was based on the play "Five Kings". It was written by Orson Welles and condensed William Shakespeare's "Richard II", "Henry IV" parts 1 & 2, "Henry V", the three parts of "Henry VI" and "Richard III" into one show. He produced the show in New York City in 1939, but the opening night, during which Part 1 was performed, was a disaster, and Part 2 was never put on. He revamped the show and revisited it in 1960. Again, it was not successful. However, this later production was used as the basis for this movie.
Notorious exploitation filmmaker Jesús Franco worked as an assistant director on this movie. He is not listed in the credits because he and Orson Welles had a falling out when Franco took it upon himself to try and secure additional financing for this movie.