This essay is the transcription of a conference given at the Metropolitan Museum of Art, New York on April 29th 2016. This research is part of a larger project on the Daniel-Henry Kahnweiler’s sequestration sales, which took place after the First World War. In order to shed new light on the history and organization of the sales, I’m trying to identify all works by Braque, Gris, Léger and Picasso, as well as their buyers. I also aim to locate them today and to create a catalog raisonné of the Cubist works that were part of these sales as a tool for researchers.