Mathematics and art through the strings as with a bird cage and to see one form within another which excited me." The artists Theo van Doesburg and Piet Mondrian founded the De Stijl movement, which they wanted to "establish a visual vocabulary elementary geometrical forms comprehensible by all and adaptable to any discipline". Many of their artworks visibly consist of ruled squares and triangles, sometimes also with circles. De Stijl artists worked in painting, furniture, interior design and architecture. After the breakup of De Stijl, Van Doesburg founded the Avant-garde Art Concret movement, describing his 1929–1930 "Arithmetic Composition", a series of four black
Helene Kröller-Müller the first people to recognise the genius of Vincent van Gogh. She eventually amassed more than 90 van Gogh paintings and 185 drawings, one of the world's largest collections of the artist's work, second only to the Van Gogh Museum in Amsterdam. She also bought more than 400 works by Dutch artist Bart van der Leck, but his popularity did not take off like van Gogh's. Kröller-Müller also collected works by modern artists, such as Picasso, Georges Braque, Jean Metzinger, Albert Gleizes, Fernand Léger, Diego Rivera, Juan Gris, Piet Mondrian, Gino Severini, Joseph Csaky, Auguste Herbin, Georges Valmier, María Blanchard,