ABSTRACT
The death of Spain’s Philip IV on September 17, 1665 left an immense monarchy under the vulnerable regency of his widow, Queen-Consort Mariana of Austria.1 Almost two decades earlier, the treaties of Westphalia in 1648 had marked a definitive watershed for Spanish involvement in the politics of continental Europe. Because of Spain’s and the Holy Roman Emperor’s weakened position as a coalition against France and Sweden during the last phase of the Thirty Years War, Spanish diplomats could no longer impose the king’s policies upon the previously solid alliance between the two branches of the Habsburg dynasty without meeting fierce opposition at the Imperial court.
