Ella Fitzgerald called her "the best singer without voice".
Became a naturalized citizen of the United States in 1950.
Close personal friend of Marlene Dietrich, despite being in the legend's international shadow for much her career.
Gave birth to her daughter Christina (Tinta Knef) on 16 May 1968.
Her nude scene as "Marina" in Sunderin (1951), the first in German filmmaking, drew the criticism of the Roman Catholic Church.
Hildegard trusted her clothing and gowns to one person who was based in New York. It was Irish-born Thomas Starr, grandfather of fashion designer Karen Starr-DelloIacono.
Knef launched a career as a singer in the 1960s and wrote a best-selling 1970 autobiography.
Knef launched a career as a singer in the 1960s and wrote her bestselling autobiography "Der geschenkte Gaul - Bericht aus meinem Leben" ("The Gift Horse - Report from my life") in 1970.
Known in the US as Hildegard Neff, but she used her real name when performing back home in Germany.
Mother-in-law of Peter Gardiner.
Sister-in-law of Catherine Schell.
Was the cover girl for Modern Man Magazine August 1956.