Louis XIV., in his distress, was naturally anxious to gain the support of so powerful an ally, who was now at Dresden at the head of fifty-three thousand veteran soldiers, ready to fall on the rear of Marlborough's army, that threatened the defensive barrier of France in the Low Countries. Every effort, accordingly, was made to gain Charles over to the French interest. The ancient alliance of France with Sweden, their mutual cause of complaint against the Emperor, the glories of Gustavus Adolphus and the thirty years' war, in which they had stood side by side, were held forth to dazzle his imagination or convince his judgment. The Swedish monarch appeared ready to yield to these efforts. He brought forward various real or imaginary grounds of complaint against the German powers, for infractions of the constitution of the empire, of which he put himself forth as the guarantee, as heir to the crown and fame of Gustavus Adolphus, as well as for sundry insults alleged to have been committed against the Swedish crown or subjects. These various subjects of complaint were sedulously inflamed by the French agents; and the weight of their arguments was not a little increased by the knowledge of the fact, that they were authorized to offer Count Piper, the prime minister of Charles, 300,000 livres (L.12,000), to quicken his movements in favour of the cabinet of Versailles, besides bribes in proportion to the subordinate ministers of the Swedish monarch.[10] Marlborough, as well he might, was extremely uneasy at this negotiation, which he soon discovered by secret information, as well as the undisguised reluctance of the German powers to furnish the contingents for which they were bound for the ensuing campaign. Indeed, it could hardly be expected that the Northern powers in Germany should send their chief disposable forces to swell Marlborough's army beyond the Rhine, when so warlike a monarch, at the head of fifty thousand men, was in the centre of the empire, with his intentions as yet undeclared, and exposed to the influence of every imaginable seduction. He dispatched, accordingly, General Grumbkow, an adroit and intelligent diplomatist, who had been sent by the King of Prussia on a mission to the Allied headquarters, to Dresden, to endeavour to ascertain the real intentions of the Swedish monarch. He was not long of discovering that Charles had assumed an angry tone towards the confederates, only in order to extract favourable terms of accommodation from them, and that Muscovy was the real object on which his heart was set. His despatches convey a curious and highly interesting picture of Charles and the Swedish court and army at this important juncture.[11] The negotiation went on for some time with varying success; but at length matters were brought to a crisis, by the King of Sweden declaring that he would treat with none but Marlborough in person.