Abstract art based on Cézanne's idea that all depiction of nature can be reduced to three solids: cube, sphere and cone. With the painting "Les Demoiselles d'Avignon" (1907), Picasso dramatically created a new and radical picture depicting a raw and primitive brothel scene with five prostitutes, violently painted women, reminiscent of African tribal masks and his own new Cubist inventions. Analytic cubism was jointly developed by Pablo Picasso and Georges Braque, from about 1908 through 1912. Analytic cubism, the first clear manifestation of cubism, was followed by Synthetic cubism, practiced by Braque, Picasso, Fernand Léger, Juan Gris, Albert Gleizes, Marcel Duchamp and
Pablo Picasso her home in Paris. At one of her gatherings in 1905, he met Henri Matisse, who was to become a lifelong friend and rival. The Steins introduced him to Claribel Cone and her sister Etta who were American art collectors; they also began to acquire Picasso and Matisse's paintings. Eventually Leo Stein moved to Italy. Michael and Sarah Stein became patrons of Matisse, while Gertrude Stein continued to collect Picasso. In 1907, Picasso joined an art gallery that had recently been opened in Paris by Daniel-Henry Kahnweiler. Kahnweiler was a German art historian and art collector who became one of