Mathieu Deldicque holds a doctorate in art history, is an archivist and paleographer, and is heritage curator and director of the Musée Condé in Chantilly. Specializing in late medieval and Renaissance art in France and Italy, he is the author of A Day at Ch'teau de Chantilly , published by Flammarion (2020). Valentin Pérez is a journalist. A regular contributor to Le Monde 's magazine M , he covers sectors such as fashion, cinema, and jewelry, and writes about the link between the luxury and cultural industries. He is also coproducer of the business show On n'arrête pas l'éco , on France Inter radio station.