Born in Brussels in 1927. After training at the Ecole nationale supérieure d’architecture et aux Arts décoratifs of Brussels, he joins the Young Belgian Painters group in 1947, and the COBRA movement in 1949. From the 60s onwards, his work achieved international renown. He has participated in dozens of exhibits and biennials, including Sao Paulo and Venice. In 1965, he spent time in New York, where he inaugurated, with the Chinese painter Wallace Ting, his celebrated Remarques marginales (Marginal Comments). In 1987, he had an exhibit at The Guggenheim Museum of New York. In 1998, the Galerie nationale du Jeu de Paume in Paris held a retrospective. He is currently preparing a major exhibit at the Musée National d’Art Moderne / Centre Pompidou.