Cubism was the most important movement of the 20th century and marked the birth of abstract art. Invented and pursued by Pablo Picasso and Georges Braque in Paris between 1907 and 1914 and inspired by the simplified landscapes of Paul Cézanne, Cubism took the revolutionary step of rejecting the 500-year-old idea that a painting was like a window, thus ruled by perspective. Instead, Picasso and Braque created more conceptual, subjective paintings that sought to represent the underlying structure of existence. The best-known Cubist works look like shattered glass in dim browns and yellows, and are composed of various sharp planes that combine to form people or objects. Cubism took its name from an insult delivered by the critic Louis Vauxcelles, who commented that one of Braque’s paintings looked as if it were “full of little cubes.” After 1910, Picasso and Braque’s Cubism was quickly adopted by many other artists in Paris and beyond and ended up being the primary influence on most or all abstract art before the outbreak of World War II.