Accredited to a Habsburg court, he likewise took a keen interest in the final stages of the reign and the succession of Emperor Rudolf II.

Three more topics occupied a great deal of his time: the struggle over the Jülich-Cleves inheritance,[2] which was set to ignite the Thirty Years War, the flight of the prince de Condé from France in objection to Henri IV's divorce and remarriage,[3] and the degree of toleration for Catholics in England and Ireland under James I.

His correspondence reveals Bentivoglio as "the skilled diplomatist,[4] polished by constant intercourse with the most refined society, as well as the mature observer," according to Ludwig Pastor.

[5] Afterwards he was nuncio to the Court of France (9 July 1616 – 1621), where he witnessed the uproars of the Regency of Queen Marie de' Medici, the fall of Concino Concini in the coup operated by Louis XIII and his favorite Charles d'Albert, the discord between the Queen-Mother and her son and the first Huguenot rebellions.

The King rewarded his services as nuncio with the appointment on 11 July 1622 to the bishopric of Riez, a position from which Bentivoglio would resign on 16 October 1625.