Marion Davies was born Marion Cecilia Douras in Brooklyn, NY in 1897.
Davies met William Randolph Hearst while she was in the Zeigfeld Follies. She became his mistress and remained so until his death in 1951.
Hearst attempted to make her a star, but unfortunately insisted on serious roles when her talent lay in comedy. Hearst's production company, Cosmopolitan, was founded primarily for Davies' films, and it eventually was absorbed by MGM.
At MGM, Davies became a vehicle for Louis Mayer's search for power. He treated her well, lavishing money and attention on her, even giving her a private bungalow on the lot. Some people felt that these rewards exceeded her worth as an actress, but not the value of the MGM publicity in the Hearst papers. Davies moved to Warner's when she didn't get to play Elizabeth Barrett Browning, but retired from films shortly thereafter.
Heart was offended by the portrayal of Davies in Citizen Kane (although Davies herself did not seem to mind). Hearst publications boycotted the movie, and it received little of the publicity it would have otherwise received.
Davies stood beside Hearst as his finances and health began to fail, offering all the gifts he had given her for his support. It is accepted that they both had deep feelings for each other. She was shunned by his family, however, and was not allowed to attend his funeral.
While living at San Simeon, Hearst and Davies gave many parties, and one of the most frequent guests was David Niven. Niven used the term "chatelaine" in reference to Davies in his autobiography, commenting on how lonely she was in the isolated mansion in between these gala events.