Cubism was a 20th century avant-garde art movement, pioneered by Pablo Picasso and Georges Braque, that revolutionized European painting and sculpture, and inspired related movements in music and literature. The first branch of cubism, known as Analytic Cubism, was both radical and influential as a short but highly significant art movement between 1907 and 1911 in France. In its second phase, Synthetic Cubism, the movement spread and remained vital until around 1919, when the Surrealist movement gained popularity.
Below you can see a few of Picasso's and Braques's paintings from quite early on until later real Cubist paintings.