Gertrude Welcker: Gertrude Welcker. Actress: Dr. Mabuse, the Gambler. Gertrude Welcker was born on 16 July 1896 in Dresden, Saxony, Germany. She was an actress, known for Dr. Mabuse, the Gambler (1922), Die Dame in Schwarz (1920) and Dämon Zirkus (1923). She died on 1 August 1988 in Danderyd, Stockholms län, Sweden.