Jorn (born Jørgensen) studied with Léger, and worked with him on murals for a pavilion by Corbusier. He met Constant at a Miró exhibition in Paris; they then founded CoBrA with Appel, Dotremont and Noiret (and the painter Corneille). Jorn was a founder member in 1957 of the Situationist International along with Debord and Bernstein, and co-authored Debord’s ‘Mémoires’, an entirely detourned document. Utzon was a friend, and designed an underground museum for him that remained unbuilt.