Here is a short section from http://smarthistory.khanacademy.org/les-demoiselles-davignon.html
Cézanne's ghost, Matisse's Bonheur de Vivre, and Picasso's ego
One of the most important canvases of the twentieth century, Picasso’s great breakthrough painting Les Demoiselles d’Avignon was constructed in response to several significant sources. First amongst these was his confrontation with Cézanne’s great achievement at the posthumous retrospective mounted in Paris a year after the artist’s death in 1907. The retrospective exhibition forced the young Picasso, Matisse and many other artists to contend with the implications of Cézanne’s art. Matisse's Bonheur de Vivre of 1906 was one of the first of many attempts to do so, and the newly completed work was quickly purchased by Leo & Gertrude Stein and hung in their living room so that all of their circle of avant-garde writers and artists could see and praise it. And praise it they did. Here was the promise of Cézanne fulfilled—and one which incorporated lessons learned from Seurat and Van Gogh, no less! This was just too much for the young Spaniard.
