 During Queen Mary's captivity in England he paid her frequent visits, and was untiring in his efforts in her service.After her death he published a long exposure of her treatment in imprisonment, interspersed with passionate denunciations of her enemies, especially John Knox and Elizabeth I of England.The title of the work is "Martyre de la Royne d'Escosse, Douairiere de France; contenant le vray discours des traïsons à elle faictes à la suscitation d'Elizabet Angloise, par lequel les mensonges, calomnies, et faulses accusations dressées contre ceste tresvertueuse, trescatholique et tresillustre princesse son esclarcies et son innocence averse."