Cubism Cubism", (from 1909 to 1914) during which time Juan Gris emerged as an important exponent (after 1911); and finally Cooper referred to "Late Cubism" (from 1914 to 1921) as the last phase of Cubism as a radical avant-garde movement. Douglas Cooper's restrictive use of these terms to distinguish the work of Braque, Picasso, Gris (from 1911) and Léger (to a lesser extent) implied an intentional value judgement. Cubism burgeoned between 1907 and 1911. Pablo Picasso's 1907 painting "Les Demoiselles d'Avignon" has often been considered a proto-Cubist work. Georges Braque's 1908 "Houses at L’Estaque" (and related works) prompted the critic Louis
Crystal Cubism towards the end of 1916, with an art world still under the pressures of war, to show the parallels between the poetic theories of Guillaume Apollinaire of Max Jacob and himself in marking the burgeoning of a new era for poetry and artistic reflection. In "Nord-Sud" Reverdy, with the help of Dermée and Georges Braque, exposed his literary theories, and outlined a coherent theoretical stance on the latest developments in Cubism. His treatise "On Cubism", published in the first issue of "Nord-Sud", did so perhaps most influentially. With his characteristic preference for offense rather than defense, Reverdy launched an attack