 When François de Bassompierre was sent to England in 1627 to regulate the differences between Queen Henrietta Maria of France and her husband King Charles I of England, Harlay de Sancy was attached to the queen's ecclesiastical household, but the king secured his dismissal.Harlay named the Bishop of Saint-Malo in 1631, for which he was consecrated in January 1632.He served in this post until his resignation on 20 November 1646.