Jennifer Jones appeared to have come out of nowhere to win the Best Actress Oscar for her first leading role as the peasant girl who had a vision of the Virgin Mary at Lourdes in The Song of Bernadette (1943).

In fact she had been set on a career as an actress since childhood, and her breakthrough was largely due to movie mogul David O Selznick - the man behind Gone With the Wind - who took personal control of her career when she was an unknown. He also became her second husband.

She went on to be nominated four more times for an Oscar.

Ms Jones - who died on 17 December 2009, aged 90 - was born Phylis Isley in Tulsa, Oklahoma, on March 2, 1919, the daughter of Phil and Flora Mae Isley, who ran a travelling theatre. She toured with her parents in vaudeville tent shows - her first role was allegedly as a peppermint candy when she was five - but they tried to steer her away from a career in performing arts.

Despite their hopes, she persuaded her father to let her attend the American Academy of Dramatic Arts in New York. A fellow student was Robert Walker, whom she married in 1939 when she was 19.

The couple returned to Tulsa, where they did radio work, and moved to Hollywood where Ms Isley - who added a second l to her name to become Phyllis - had small parts in a B western, New Frontier, with John Wayne , and a serial, Dick Tracy’s G-Men.

Mr Walker had even less success and the couple returned to New York where Ms Isley modelled for a while before landing an audition for Mr Selznick. Although she did not get the part he saw her potential and put her under contract.

From then until his death in 1965, he controlled every step of her career, changing her name to Jennifer Jones and sending her back to New York to polish up her diction and acting at the Academy.

He marketed her as a star before she was one and convinced Fox to star her in The Song of Bernadette . Her peformance won huge acclaim and she scooped the best actress oscar ahead of stars like Ingrid Bergman who had been nominated for her performance in For Whom the Bell Tolls. Ms Bergman said of The Song of Bernadette : "I cried all the way through, because Jennifer was so moving and because I realised I had lost the award."

Soon after this, Ms Jones and Mr Walker were divorced and Mr Selznick's own trouble marriage to Irene, the daughter of the MGM boss Louis B. Mayer, ended in 1945.

Ms Jones and Mr Selznick were married in 1949. He continued to cast her in his own films and lend her to other studios. Her long list of film credits included Madame Bovary (1949), Gone to Earth (1950), Carrie (1952) and Tender Is the Night (1962). She starred in only two comedies but many consider them among her best work - Cluny Brown (1946) and John Huston 's Beat the Devil (1954).

She received a supporting actress Oscar nomination for Since You Went Away , and lead actress nominations for Love Letters, Duel in the Sun and Love Is a Many-Splendored Thing .

With Selznick's death in 1965, her acting career petered out. She made only three more films. The last, The Towering Inferno (1974), saw her in a cameo role as one of those trapped in a burning skyscraper.

In 1971 Jennifer Jones married the multi-millionaire industrialist Norton Simon. He died in 1993.

With Robert Walker, Jennifer Jones had two sons – Michael, who predeceased her, and Robert Walker Jr, who also became an actor. Her daughter, Mary Selznick, died aged 21 in 1976. She also left eight grandchildren and four great-grandchildren.