A French painter, theorist, writer, critic and poet, who, along with Albert Gleizes, developed the theoretical foundations of Cubism.

His earliest works, from 1900 to 1904, were influenced by the Neo-Impressionism of Georges Seurat. Between 1904 and 1907, he worked in the Divisionist and Fauvist styles with a strong Cézanne influence, leading to some of the first proto-Cubist works. From 1908, he experimented with the faceting of form, a style that would soon become known as Cubism. Before the emergence of Cubism, painters worked from the limiting factor of a single viewpoint. Cubism introduced the idea of representing objects as remembered from successive and subjective experiences within the context of both space and time, as first suggested in his writings of 1910.