Chalais had a friend, the Commandeur de Valençay, a younger brother of that Valençay whose carelessness after the capture of the ridge of Saint-Denis at Montpellier had entailed so much loss of life, and to this gentleman, on the eve of the execution of the plot, he was imprudent enough to disclose it. He believed that he would find in him a sympathetic listener, since, though he had not yet declared himself, he had always appeared well disposed towards the cause. But, to his consternation, Valençay, either from the hope of gaining the Cardinal’s favour or from genuine disgust, professed the utmost horror and indignation; “reproached him with his treason, in that being one of his Majesty’s own Household he dared to make an attempt upon the person of his first Minister,” and insisted that Chalais should forthwith accompany him to Fleury and warn Richelieu of the danger which threatened him. Chalais, in despair, obeyed, and assured the Cardinal that he had always abhorred the plot and resolved to denounce it. Richelieu believed, or affected to believe, him, and when he offered to reveal to his Eminence any further intrigues against him, accepted his services and promised to obtain for him the coveted post of Colonel of the Light Cavalry.
The Cardinal sent Valençay to Fontainebleau to inform Louis XIII and the Queen-Mother; and the King at once despatched a troop of horse to Fleury for the protection of his Minister; while Marie de’ Medici sent the gentlemen of her Household. At dawn a number of Gaston’s officers arrived at Fleury, ostensibly, to announce the approaching arrival of their master and to assist in preparing for his reception; in reality, to serve as the advance-guard of the conspirators. His Eminence received them very courteously, expressed his sense of the honour which the prince proposed to do him, and then, ordering his coach, set out for Fontainebleau, accompanied by more than a hundred horse, “to escort his Royal Highness.”
His Royal Highness was considerably astonished when the Cardinal presented himself at his levée that morning, and mildly reproached him with not having given him longer notice of the visit with which it was his intention to honour him. In order to avert suspicion as to his destination, Monsieur had announced his intention of hunting that day; and, as Richelieu withdrew, after handing the prince his shirt—a duty which was always performed by the prelate or noble of the highest rank present—he remarked significantly: “Monsieur, you have not risen early enough this morning; you will find that the quarry is no longer at home.” Then Gaston knew that someone had betrayed him.
Thoroughly frightened, the pusillanimous prince passed from treachery and conspiracy to base submission, “with the levity of a selfish and thoughtless child, destitute of both moral sense and courage,”[35] and on May 31, in the presence of the King, the Queen-Mother and the Cardinal, he signed and swore on the Gospels to observe faithfully a compact drawn up by Richelieu, in which he engaged that “no counsel should ever be proposed or submitted to him by anyone whomsoever of which he would not advise his Majesty; that he would not keep silence concerning even the most trifling words that were spoken to him with the object of arousing his resentment against the King and his advisers, and that he would love and esteem those whom the King and the Queen-Mother loved.”
Gaston had sworn to and signed everything that had been put before him, but, being as faithless as he was cowardly and selfish, he had not the remotest intention of executing his engagement. In fact, while swearing to inform his brother of everything contrary to his service that might come to his knowledge, he said not a word of the great conspiracy which, from the foot of the throne, had extended over the whole kingdom and far beyond its borders; and, when he again found himself among his partisans, he disclosed nothing of what had just taken place, renewed all the promises which he had made them, and continued to preside over their deliberations.
Chalais likewise kept his counsel, and the conspirators appear to have entertained no suspicion that they had a traitor in their midst, and probably attributed the Fleury fiasco to some vague warning furnished the Cardinal by one or other of the many secret agents whom he had in his pay. Had Chalais promptly avowed his enforced betrayal of their designs, they would certainly have proceeded with a great deal more caution, even if they had not decided to abandon the enterprise altogether. But, for a while, he appears to have been of opinion that his wisest course was to say nothing to his friends, and to keep, at least to some extent, his promise to report any fresh developments to the Cardinal; and when at length his secret was forced from him by the address of Madame de Chevreuse and he was involved anew in the conspiracy, its leaders were already hopelessly compromised.
Whether by Chalais or by one of his secret agents, Richelieu’s attention was directed to the Duc de Vendôme, whose movements he caused to be closely watched. Vendôme had resolved to offer Monsieur an asylum in his government of Brittany, and the Cardinal ascertained that he was secretly preparing for war, and that he was in communication with the authorities of La Rochelle. Recognising the importance of stifling at its birth the insurrection in a great province so close to La Rochelle and so exposed to an English invasion, he persuaded the King to proceed thither in person to re-establish his threatened authority. But, since he was doubtful if his Majesty could be brought to consent to the arrest of his half-brothers, the duke and Grand Prior, he resolved to ascertain how far he was prepared to support him, and accordingly requested permission to retire, on the ground of failing health. Louis declined his resignation in a letter which was equivalent to an oath of fidelity from the King to his Minister, and concluded with these words: “Be assured that I shall never change, and that, whoever may attack you, you shall have me for second.”
Armed with this promise, Richelieu no longer hesitated to represent to the King the necessity of arresting the natural sons of Henri IV, and Louis at once assented. On learning of the approach of the Court, the Duc de Vendôme, who was at Nantes, became very uneasy; but since he could not abstain from paying his homage to his sovereign without practically proclaiming himself a rebel, he charged his brother the Grand Prior to obtain an assurance of safety from the King. “I give you my word,” said Louis, “that he will come to no more harm than you.” Deceived by this gross equivocation, the duke joined the Court at Blois, where it had arrived on June 6, and was very graciously received. But, two days later, both he and his brother were arrested in their beds by Du Hallier, Captain of the Guards, and conducted to the Château of Amboise, where they were very strictly guarded (June 12).
It would appear that, at this juncture, Richelieu was very far from being aware of the wide range of the conspiracy or of all its chiefs; otherwise, he would scarcely have left the Comte de Soissons behind in Paris to command in the name of the King, or have allowed Monsieur to remain in the capital, subject to all the influences that were being brought to bear upon him to induce him to raise the standard of revolt. However, two or three days after the arrest of the Vendômes, the King received warning that Soissons was meditating the abduction of Mlle. de Montpensier, who had also remained in Paris, upon which he sent Fontenay-Mareuil in all haste to Paris to bring the young lady to the Court, and orders to Bassompierre, Bellegarde, and d’Effiat to accompany them, with as many of their attendants as they could bring. Bassompierre, who was just starting for Blois, had sent all his suite on in advance, but the other two nobles were able to supply a sufficiently-strong guard, under whose escort Mlle. de Montpensier left Paris with the Duchesse de Guise.