During the rise of the Nazi regime in the Thirties, Klee became a target of their campaign against ‘degenerate art’. In 1933 Klee was stripped of his teaching post at the Bauhaus and fled to Switzerland where he fell ill, produced far fewer paintings, and died in 1940. More than a hundred of his works were confiscated from German museums and collections. Walpurgis Night is the night that marks the transition from winter to spring, falling on the eve of the first of May. In folk tradition, witches would gather on the Brocken, the highest of the Harz Mountains, to perform rituals to ward off evil. According to his son Felix, such legends exerted a particularly strong influence on Klee’s work.