 Leigh became pregnant in 1956 and withdrew from the production of Coward 's comedy South Sea <unk> . The day after her final performance in the play she <unk> and entered a period of depression that lasted for months . The same year Olivier decided to direct and produce a film version of The Sleeping Prince , retitled The Prince and the <unk> . Instead of appearing with Leigh , he cast Marilyn Monroe as the <unk> . Although the filming was challenging because of Monroe 's behaviour , the film was appreciated by the critics . 
