[3] Dorn was born in Scheveningen, The Hague, Netherlands in 1901 and made his stage début at age 14[4] in Dutch productions.

He had lead roles in De Big van het Regiment (1935), The Crosspatch (1935), Op Stap (1936), and Rubber (1936).

[9] Koster was at Universal and Dorn made three films for that studio: Enemy Agent (1940), Ski Patrol (1940), and Diamond Frontier (1940).

At MGM he had a support in Tarzan's Secret Treasure (1941) and they put him in a Dr. Kildare film, Born to be Bad, that had to be reshot when star Lew Ayres was fired due to being a conscientious objector.

At Warners he starred in Escape in the Desert (1945), a remake of The Petrified Forest replacing Zachary Scott.

Back in Germany, Dorn starred in Behind Monastery Walls (1952), Towers of Silence (1952), Dreaming Lips (1953) and Salto Mortale (1953).

[citation needed] After an accident on stage, he retired in 1965 and spent the next 10 years of his life in his home in California.

[citation needed] Dorn died of a heart attack at the Motion Picture & Television Country House and Hospital[19] in Woodland Hills, Los Angeles, California, on 9 May 1975.