 In 1605 he became coadjutor, with right of succession, of his uncle Henri d'Escoubleau de Sourdis, bishop of Mallezais, and in 1607 he had the honor of baptizing the duke of Orléans, second son of King Henry IV of France.In 1615, he officiated at the wedding of Elisabeth of France with Infant Felipe (future Philip IV of Spain), and of Louis XIII, king of France, with Infanta Anne of Austria, Felipe's sister, in St. Andrew's Cathedral.He was succeeded as Archbishop at his death by his brother, Henri de Sourdis.