Her father, a decorated First World War veteran, died when she was only six months old, and her mother moved to Berlin and worked in a factory.
After she had a successful screen test, she went to the State Film School at Babelsberg, Berlin, where she studied acting, ballet, and elocution.
Joseph Goebbels, who was Hitler's propaganda minister, wrote to her and asked to meet her, but Knef's friends wanted her to stay away from him.
During the Battle of Berlin she dressed as a soldier to stay with her lover, Ewald von Demandowsky, and joined him in the defence of Schmargendorf.
Von Demandowsky was executed by the Russians on 7 October 1946, but before that he secured for Knef the protection of the well-known character actor Viktor de Kowa in Berlin.
She wrote that it was totally absurd that people considered her nudity to be scandalous, as Germany was the country that had created Auschwitz and had caused so much horror.
[7] David O. Selznick invited her to Hollywood, but she refused to agree to the conditions of the contract which reportedly included changing her name to Gilda Christian and pretending to be Austrian rather than German.
[3] Knef was cast as Hilde in the Hollywood film Decision Before Dawn (1951), directed by Anatole Litvak and co-starring with Richard Basehart and Oskar Werner in a story about the later part of World War II.
Knef had acted in at least 30 films in the United States and Europe, but her triumph came in New York when she played Ninotchka, an unemotional Soviet commissar.
In 1963 she started a concert and recording career,[1] and she surprised her audiences with the deep, smoky quality of her voice and with lyrics that were written by herself.
Knef not only achieved international best-seller status, her books were also widely praised by critics because her autobiographies were "better-than-the-average celebrity's".
[5] The book doesn't try to persuade the public, depicting a made-up celebrity's adventures, but truthfully recounts her struggles as a German woman who grew up in Berlin under the Nazis.The Gift Horse: Report on a Life was translated to English by Knef's second husband, David Anthony Palastanga.
The Verdict describes in great detail the hospital scenes as well as the doctors and nurses in New York, Los Angeles, Zürich and Hamburg, where she was hospitalised.