This special issue collects the papers and talks delivered at the international conference "Was heißt: Foucault historisieren?" (What is: Historicizing Foucault?) at the University of Zurich on March 19–21, 2015. The collection attempts both to historicize Foucault and to historicize Foucault. That is, the focus not only lies on the historical contexts of Foucault's thought (e.g., cold war, cybernetics, Maoism, structuralism), but also on the question if we should start to forget Foucault (as Baudrillard already suggested in a polemic from 1977). Do Foucault's concepts, thirty years after his death, still enable us to understand our contemporary world? Or do we have to adjust, to update the Foucauldian tool-box?