Constant and Jorn originally met at a Miró exhibition in Paris. In 1948 he also met Appel, Noiret and Dotremont, and collectively (including Jorn, and the painter Corneille) they founded CoBrA. He shared a Paris apartment with Appel. He corresponded regularly with Debord on Situationist matters, collaborated on an exhibition project with Rietveld, and got involved with Lefebvre, whose ‘Critique of Everyday Life’ had been an inspiration for CoBrA.