Cubism was an influential early 20th century avant-garde art movement that revolutionized European painting and sculpture. Led by Pablo Picasso and Georges Braque, Cubism was characterized by the geometric fragmentation and synthetic reassembly of forms to depict subject matter from multiple viewpoints in the same canvas. Major influences on Cubism included African tribal masks, Cézanne's compositions, and Fauvism. Cubism evolved from an early phase of angular, simplified still life subjects to a later incorporation of collage materials and brighter colors. Key Cubist artists beyond Picasso and Braque included Juan Gris, Fernand Léger, and Jean Metzinger.