The Spanish Cabinet was, moreover, desirous of widening the breach between the Catholics and Protestants of France, an attempt in which it was zealously seconded by the Pope, who was readily persuaded that no measure could be so desirable for the accomplishment of such a purpose as a union between the two crowns.  Thus the objections which had appeared insuperable to Henri IV lost all their weight in the mutual anxiety of Marie and Philip to secure the advantages which each sought to gain; and, as the youth of Louis XIII forbade the immediate celebration of the marriage, a private pledge was exchanged between the ministers of France and the Spanish envoy, that the Regent should not interfere with the measures of the House of Austria in Germany, while Spain should refuse all support to the malcontents in her own kingdom; and this mutual understanding once established, the double alliance was concluded.[71]

In the midst of the important interests by which the mind of Marie de Medicis was at this period occupied, a fresh demand upon her attention was made by Madame de Verneuil, who on the 15th of September laid before the Comte de Soissons, the Cardinal de Joyeuse, and the Duc d’Epernon, the written engagement which she had received from the Duc de Guise, and urged its enforcement.  Her claim was warmly espoused by M. de Soissons, who at once declared the document to be valid and unanswerable; while it was admitted by all by whom it was examined to be strictly legal in form, and to authorize her in demanding its ratification.  Unlike that which she had previously extorted from Henri IV, the promise which the Marquise now produced was not only signed by M. de Guise himself, but also by two notaries, a priest, and several witnesses.  Unfortunately, however, whether by accident, or intention on the part of the Duke, both the notaries by whom it had been attested were aged men, one of whom had subsequently died; while the other had become so imbecile that when interrogated upon the subject, he first doubted, and subsequently denied, all knowledge of the transaction; but as these contingencies did not affect the signature of M. de Guise himself, his position was sufficiently embarrassing; and the rather that, his passion for the Marquise having been long extinguished, he had become the acknowledged suitor of the Dowager Duchess of Montpensier.

There can be little doubt that had Henri IV still lived Madame de Verneuil would have been enabled to enforce her claim, as that monarch would not have suffered so admirable an opportunity of mortifying the Guises to have escaped him; and thus individual imprudence would have afforded him a triumph which the fortune of arms had hitherto denied, and the most jealous watchfulness failed to secure; but his death had changed the position of all the parties interested in the affair, and Marie de Medicis looked upon it with very different feelings.  Her old and still existing hatred of the Marquise was renewed by an exhibition of arrogance which recalled to memory some of the most bitter moments of her existence; and her pride as a sovereign was revolted at the prospect of seeing the woman by whom her peace had been destroyed elevated to the rank of a Princess of the Blood, and placed beside the very steps of her throne.