Mary Rose (1964)
Hitchcock had long desired to turn J. M. Barrie's 1920 play Mary Rose into a film. In 1964, after working together on Marnie, Hitchcock asked Jay Presson Allen to adapt the play into a screenplay. Hitchcock would later tell interviewers that his contract with Universal allowed him to make any film, so long as the budget was under $3 million, and so long as it was not Mary Rose. Whether or not this was actually true, Lew Wasserman was not keen on the project, though Hitchcock never gave up hope of one day filming it.
Read more about this topic: List Of Unproduced Hitchcock Projects