This research project consists of an intellectual history and philosophical investigation of “Nietzschean socialism” in the prewar period and focuses on the position of Charles Andler (1866-1933). Although “left-wing Nietzscheanism” sounds like an oxymoron today, Andler synthesized the collusion of two trends: the need for a scholarly renewal of socialist thought through a critique of Marxism and the discovery of Nietzschean individualistic aristocratism. My question is how such a pairing was possible. I believe this research will show that Andler’s position emerged through socialist, feminist, and anarchist circles—most notably that of Malwida von Meysenbug (1816-1903)—and that left-wing radical intellectual movements were decisive in the cultural transfers of Nietzsche’s ideas; that this position did not rest on a distortion or occultation of Nietzsche’s published works and that left-leaning positions may still produce a sound interpretation of Nietzsche’s thought; and that the possibility of Nietzschean socialism was eclipsed by an ideological construction that bound Nietzsche to the far right. This should show that it is now necessary to return to Andler in order to shed light on the stakes surrounding the interpretation of Nietzsche in Europe before and after the 1930s and to open up the interpretative possibilities of Nietzsche’s ideas.