(b Utrecht, 26 Nov. 1876; d Blaricum, 13 Nov. 1958). Dutch painter and designer. After working for eight years in stained-glass studios, he studied painting in Amsterdam, 1900–4. His early work was influenced by Art Nouveau and Impressionism, but from about 1910 he developed a more personal style characterized by simplified and stylized forms: his work remained representational, but he eliminated perspective and reduced his figures (which included labourers, soldiers, and women going to market) to sharply delineated geometrical forms in primary colours. In 1916 he met Mondrian and in 1917 he was one of the founders of De Stijl. At this time his work was purely abstract, featuring geometrically disposed bars and rectangles in a style close to those of Mondrian and van Doesburg.