Muriel Box was born Violette Muriel Baker in New Malden, Surrey, on the outskirts of London, England. She originally hoped to become an actress or ballet dancer. When these careers did not work out, she became a typist and then a continuity girl for British International Pictures. In 1933, she married Sydney Box, a journalist with whom she collaborated on nearly 40 short plays before the start of World War II. Their production company, Verity Films, first produced short propaganda films, including The English Inn (1941), her first directing effort. She went on to direct 15 films between 1949 and 1964, both comedies and dramas. The couple achieved their greatest joint success with box-office hit The Seventh Veil (1945), for which they won an Academy Award for Best Original Screenplay. After the war, she was in charge of the scenario department at Gainsborough Pictures, writing scripts for light comedies. In 1951, she and her husband founded London Independent Producers, which gave her more opportunities to direct. Her credits included The Beachcomber (1954), The Passionate Stranger (1957), The Truth About Women (1958) and her final film, Rattle of a Simple Man (1964). She was one of very few female directors in the British film industry and often encountered prejudice and condescension. She left filmmaking to write novels and created Femina, a successful publishing house. After she and Sydney Box divorced in 1969, she married Lord Gardiner, a former Lord Chancellor of England. Her last book was about him, Rebel Advocate: A Biography of Gerald Gardiner (1983).