When Marcel Duchamp invented the readymade 100 years ago, few could have predicted that these random objects taken from everyday life would have such a lasting influence on art. examines Duchamp’s readymades from two perspectives, beginning with the genesis and consistency of Duchamp’s concept in the first 50 years of the “readymade century,” 1916 to 1964. The second part, “Readymade Exposition,” describes the history of the readymade’s reception, which extends far beyond Duchamp’s lifetime. The editions of Duchamp’s readymades as multiples and the exhibition of Andy Warhol’s Brillo Boxes constitute the hinge between the two sections. Occurring at the same time, independently of one another, these two events in 1964 mark a turning point in the middle of the readymade century that has direct relevance for contemporary artistic practices of the “already made.”