Working almost continuously throughout a 60-year-long career, Mayne was known as a versatile character actor, often playing suave villains and aristocratic eccentrics in films like The Fearless Vampire Killers, Where Eagles Dare, Barry Lyndon, and Benefit of the Doubt.

He stayed with his aunt, Li Osborne (1883–1968), nee Luisa Friedericka Wolf, a well-known German theatre and film portrait photographer.

His parents were detained briefly in Buchenwald but, due to his mother's British family connections, were able to leave Germany for Britain, where they settled permanently.

[5] Later, Mayne moved to the United States and played the semi-regular role of Albert Grand in the TV series Cagney and Lacey.

[6] In 1983, he played the role of Ludwig Rosenthal, a wealthy Jewish merchant persecuted and dispossessed by the Nazis, in Winds of War, a television miniseries based on the eponymous novel by Herman Wouk.