Belgian painter, active mainly in Paris. Born in Liège, he studied drawing at the Amsterdam Academy, 1940–43, but he was self-taught as a painter. In 1948 he was one of the founders of the *Cobra group and in 1950 he moved to Paris with his fellow member Karel *Appel. His work of this time was typical of the Cobra style—brilliant in colour and vigorous in brushwork, with child-like imagery suggesting mythical beings. During the 1950s he gradually abandoned figurative references for a swirling abstract style, but in the 1960s he reintroduced the imagery of his Cobra period.