 The son of René Legardeur de Tilly and Catherine de Cordé, he was born at Thury-Harcourt and came to New France in 1636 with his brother Pierre.He married Geneviève, the daughter of Jean Juchereau de Maur, in 1648.In partnership with François Byssot de la Rivière and Jean-Paul Godefroy, Tilly hunted seals at Tadoussac and traded in beaver pelts.