Polish abstract painter and art theorist. He was born at Minsk in Belarus and fought in the Russian army in the First World War, losing an arm and a leg in 1915. In hospital he met the sculptor Katarzyna Kobro (1898–1951), also Russian-born, who became his wife. After the war he studied in Moscow, 1918–19, then was assistant to Malevich at the art school in Vitebsk before settling in Poland in 1922. In 1923 he organized the first exhibition of modern art in Poland, in Vilnius (now in Lithuania), and in 1924 he was one of the founders of the Constructivist group Blok, which published a magazine of the same name. He wrote several theoretical works, of which the most important, published in 1928, was the book Unizm w malarstwie (Unism in Painting), in which he expounded a new system of painting called ‘Unism’. He claimed that in order to be seen as an optical unity a canvas should not be divided into sections by lines, masses, or rhythms, but instead should consist of an all-over pattern. ‘Line divides—the purpose ought not to be the division of the picture, but its unity, presented in a direct way: optically.’ Therefore the painter must renounce line, rhythm (‘because it exists only in the relations of independent parts’), oppositions, contrasts, and division (‘because it concentrates and intensifies the forms around the contour, and cuts the picture in sections’). He claimed that with Unism he had gone beyond Malevich in abstraction, because not only were his pictures *‘non-objective’ in the sense of having no subject, they had no images either (i.e. he had banished Malevich's squares and similar basic forms). In this way he anticipated Minimal art.
In 1930 Strzemiński helped to found another avant-garde group, a.r. (revolutionary artists), in Łódź. After the Second World War he painted a series of vividly coloured works in which he depicted ‘after-images’—images left in the eye after it has been looking at a bright light source. From 1945 to 1950 he taught art history at the Higher School of Fine Arts in Łódź. His work is well represented in the Sztuki Museum, Łódź.