Dutch painter, sculptor, draughtsman, and printmaker, born in Amsterdam, where he studied at the Academy, 1939–42. He was a member of the Cobra group, but from the early 1950s he turned more to Constructivist sculpture. From 1956 to 1969 he devoted much of his time to work on an ideal urban project, Nieuw Babylon (New Babylon), for which he made many designs and models. In the 1970s he returned to painting. He died in Utrecht.