Karel Appel studied at the Royal Academy of Fine Arts in Amsterdam. His first solo exhibition took place in 1946 in Groningen. In the years following the end of World War Two he developed his own unique style of art, using found objects and pieces of timber in assemblages and other artworks. His earliest themes were associated with imagery of childhood, often featuring grotesque humans, monsters and animal forms. He was one of the founders of the Dutch Experimental Group in 1948, along with Guillaume Corneille and Constant Nieuwenhuys. All three artists left Amsterdam and moved to Paris, where they joined with Belgian and Danish artists to form the Cobra international art group. In 1949 he created a mural for a cafeteria located in the City Hall in Amsterdam, but public disapproval caused this to be covered over in whitewash for the next ten years. At the 1954 Venice Biennale he awarded the UNESCO prize.