English painter, son of the painters William Nicholson and Mabel Pryde. Studied briefly at Slade School in 1911. Largely self-taught, he began to paint seriously ca. 1920 after marrying Winifred Dacre. Second marriage to Barbara Hepworth ended in 1951. Center of group in St. Ives, Cornwall. After third marriage, to Felicitas Vogler in 1958, he settled in the Ticino (Switzerland). Austere geometric paintings and reliefs were among the most influential abstract works in British art. He traveled extensively in Europe between 1911 and 1914 and in 1917 visited California, keeping a detailed record in sketches of architecture and landscape. Instrumental in introducing continental modernism into England. His first semiabstract still lifes reflect his exposure to Synthetic Cubism in Paris. In 1933 he met the Dutch painter Piet Mondrian, under whose influence his work took on a cooler geometry; typical of this period are his low reliefs of whitewashed circles and rectangles. Coeditor with Naum Gabo and J.L. Martin of Circle, a manifesto published in 1937 to promote Constructivism in England. Later work demonstrates an increasing concern with texture and with simple, isolated representation through silhouette.