Dada in Cologne emerged in autumn 1919 when the terms of the Treaty of Versailles placed the city under British military control. The movement's defiant tactics befit a public disillusioned by the continuation of military authority and censorship in the postwar period. Dadaists in Cologne experimented with various Dada techniques including photomontage, use of everyday objects as artistic materials, and reliance on absurd or even incoherent juxtapositions. They exploited the Dada fascination with the unconscious, producing images that reveal traumatized psyches.
The central figure within Cologne Dada was Max Ernst. His own work, which reflected his university studies of art history and psychology, as well as his World War I battle experience, conjured up fantastical dream worlds with disparate parts. Calling himself "Dada Ernst"—a pun on the German meaning of his last name ("serious")—the artist believed that beneath its absurdity, Dada had an earnest point. The moral underpinning is suggested in a photomontage of 1920, in which Ernst collaged human arms atop the wings of an airplane, conflating the corporeal and industrial—a recurring Dada theme. In the lower corner, three civilians demonstrate how arm holds would be used to carry wounded soldiers, an unsettling reminder of the destructive capability of World War I's new technologies.
Ernst organized several Dada exhibitions that brought Dada's provocations to public notice in Cologne. The Dada-Early Spring exhibition, planned after Ernst and Johannes Baargeld were barred from showing their work in a supposedly open, jury-free exhibition, was scandalous. To view the show, which had been mounted in a pub, visitors had to pass by the urinals and listen to a recital of lewd poetry. The show further antagonized its audience, coaxing their aggressions by encouraging them to destroy an Ernst sculpture to which a hatchet was attached. The Cologne police closed the exhibition on the grounds of obscenity, although those charges were eventually dropped. Ernst's jubilant poster Dada siegt! (Dada Triumphs!) celebrates the reopening of the exhibition.