The Austrian artist Otto Mühl (Grodnau, Austria, 1925 - Olhao, Portugal, 2013) was one of the principal exponents of Viennese Actionism. His artistic practice was an open war against traditional painting, materials and processes. Mühl reacted to the canvas in a violent way, inflicting it with tears and cuts, and was also eager to abandon two-dimensionality in favour of space, through actions that involve the use of the body. Merging ritualistic and grotesque elements, Mühl dedicated himself to the production of assemblages and creations that he himself calls 'Materialaktion'. In these, the function of everyday objects is changed, as part of the work of art, in favour of the artist’s own intentions. From 1963, Mühl dedicated himself to performance, which, under the influence of Allan Kaprow, he called happenings; and he used the same objects in these. Art, for Mühl, was an energetic action aimed at revolutionising and liberating the intellectual, political and religious boundaries that restrict society and repress all vital drive, destroying the concept of freedom.