In studies of the twentieth-century avant-garde, scholars have already identified particular formal devices that play a crucial, dominant role. These include cubist dissection of an object and the analysis of motion in Italian Futurism, as well as such devices as the shift (sdvig) of Russian Cubo-futurism, one which led to formal as well as semantic experiments in literature and painting. My paper will examine another such key feature that has not thus far received much attention—the avant-garde gesture. By gesture here is meant an avant-garde act, which precedes any theorizing, provoking the public to respond to new forms of artistic expression. These gestures effectively express an avant-gardist position in relation to a traditional view of art as well as to reality. The gesture is in each case radical and has an element of theatricality. The main goal of the paper is to establish a genealogy of the avant-garde gesture and to argue that it appears in various avant-garde movements regardless of their national origin. The paper follows the avant-garde gesture from first, the Italian Futurist manifestoes, through Russian Futurism (here the principal example is the Futurist opera Victory Over the Sun), and moving further through Dadaism and Surrealism to the first film of Jean-Luc Godard (Breathless, 1959). After analyzing selected passages from manifestoes, opera and film the paper arrives at the conclusion that the most radical avant-garde gesture is generally connected with the symbolic debunking of those primal sources of light and inspiration—the moon and the sun. The paper goes on to argue that the central unifying feature of the avant-garde, expressed in such gestures, is a radical dismissal of not only conventional values, but of the world order itself as symbolized by these two major sources of light and life. In other words , such gestures are not just formal features, but are central expressions of the avant-garde aesthetic.