This movie is loosely based on a real incident. In the late 1910s and early 1920s, Dolly Oesterreich kept her lover, Otto Sanhuber in the attic where he lived for many years. Her husband Fred ran a company that made aprons. Otto even moved with the couple from Milwaukee, Wisconsin to Los Angeles, California to stay above his lover. Unfortunately, the real story doesn't have the happy ending of the movie.
This movie was made in 1966. Its release was delayed for more than two years, and its British opening was in very close proximity to that of Director Joseph McGrath's next movie, 30 Is a Dangerous Age, Cynthia (1968).
Second time in two years that Sir Richard Attenborough played a character called "Blossom". He also played circus owner Albert Blossom in Doctor Dolittle (1967).
During filming, Sir Richard Attenborough offered Shirley MacLaine the part in Gandhi (1982), which was played by Candice Bergen.
James Booth wears a red military jacket, a nice nod to his appearance in the film Zulu (1964).