René van Vooren was the Thespian pseudonym of René Sleeswijk Jr., born in the Dutch metropolis Amsterdam on 21 April 1931 as son of theater producer René Sleeswijk Sr., a stage name assumed to avoid utter confusion. In the 1950s he worked with several Dutch artists, including Tom Manders. In 1966 he joined the duo which made his name, De Mounties, after the death of the previous straight man, Fred Plevier. Although they weren't friends, Piet Bambergen (loud, short and fat) and René Van Vooren privé (tall and distinguished, resulting in an inverted Laurel and Hardy- look) proved a magical comical duo on stage. His theatre successes, all co-starring with Piet Bambergen, included: Drie in de pan (also starring Joke Bruys), Goeie Buren (Rudi Falkenhagen, John Leddy and Diana Dobbelman), Huwelijk in de steigers (Rudi Falkenhagen, Carry Tefsen), Lief zijn voor elkaar and Privé voor twee (Rudi Falkenhagen and Marlies Alcmaer).