With over 1,500,000 years of history, Russia has accumulated a rich cultural heritage influenced by a long and complex political and religious history. One of the focal points of the nation's culture is visual art, which encompasses a number of art forms: architecture, painting, craft, and many others. One of the most important forms of Russian painting is icons, which have been created since the late 10th century; these were painted on wood and featured religious symbolism, reflecting the nation's conversion to Orthodox Christianity. 1890 to 1930 marked the Russian avant-garde period in art, which encompassed a number of different movements, from Cubo-Futurism to Suprematism. This period crossed over with the Soviet Art era, resulting in a combination of new artistic movements and Soviet propaganda. A key example of this is El Lissitzky's 'Beat the Whites with the Red Wedge', commenting on the Russian Civil War using Constructivism.