The experiences of World War II had only a brief impact on the work of young, politically orientated Norwegian painters, and soon after the war they joined an international wave of abstract and non-figurative painting. The postwar generation used expressions completely freed of any boundaries, which had proved to be misused by Nazis and Facists. Despite strong opposition amongst the Norwegian public, abstract expressionism started to develop during the 1950s with the work of younger artists such as Ludvig Eikaas (b1920), Jakob Weidemann (b1923), Knut Rumohr (b1916), Tore Heramb (b1916), Gunnvor Advocaat (1912-1997), Anna Eva Bergmann (1909-1987), Finn Christensen (b1920), Inger Sitter (b1929) and Lars Tiller (1924-1994). After 1960 Olav Strømme developed expressionism in a strongly abstract manner and Gunnar S Gundersen (1921-1983) used an original language of symbols within the framework of strict geometrical rules. The colourful, organic abstractions of Willy Storn (b1936), rooted in the Surrealism of the 1930s, represented the most original work of this era.