Richter believed that the artist’s duty was to be actively political, opposing war and supporting the revolution. His first abstract works were made in 1917. In 1918, he befriended Viking Eggeling, and the two experimented together with film. Richter was co-founder, in 1919, of the Association of Revolutionary Artists (“Artistes Radicaux”) at Zürich. In the same year he created his first Prélude (an orchestration of a theme developed in eleven drawings). In 1920 he was a member of the November group in Berlin and contributed to the Dutch periodical De Stijl.
Throughout his career, he claimed that his 1921 film, Rhythmus 21, was the first abstract film ever created. This claim is not true: he was preceded by the Italian Futurists Bruno Corra and Arnaldo Ginna between 1911 and 1912 (as they report in the Futurist Manifesto of Cinema),as well as by fellow German artist Walter Ruttmann who produced Lichtspiel Opus 1 in 1920. Nevertheless, Richter’s film Rhythmus 21 is considered an important early abstract film.