Negotiations were now opened at Munster between the several belligerents.  The republic was, however, the last to send its plenipotentiaries there; having signed anew treaty with France, by which they mutually stipulated to make no peace independent of each other.  It behooved the republic, however, to contribute as much as possible toward the general object; for, among other strong motives to that line of conduct, the finances of Holland were in a state perfectly deplorable.

Every year brought the necessity of a new loan; and the public debt of the provinces now amounted to one hundred and fifty million florins, bearing interest at six and a quarter per cent.  Considerable alarm was excited at the progress of the French army in the Belgian provinces; and escape from the tyranny of Spain seemed only to lead to the danger of submission to a nation too powerful and too close at hand not to be dangerous, either as a foe or an ally.  These fears were increased by the knowledge that Cardinal Mazarin projected a marriage between Louis XIV. and the infanta of Spain, with the Belgian provinces, or Spanish Netherlands as they were now called, for her marriage portion.  This project was confided to the Prince of Orange, under the seal of secrecy, and he was offered the marquisate of Antwerp as the price of his influence toward effecting the plan.  The prince revealed the whole to the states-general.  Great fermentation was excited; the stadtholder himself was blamed, and suspected of complicity with the designs of the cardinal.  Frederick Henry was deeply hurt at this want of confidence, and the injurious publications which openly assailed his honor in a point where he felt himself entitled to praise instead of suspicion.

The French labored to remove the impression which this affair excited in the republic; but the states-general felt themselves justified by the intriguing policy of Mazarin in entering into a secret negotiation with the king of Spain, who offered very favorable conditions.  The negotiations were considerably advanced by the marked disposition evinced by the Prince of Orange to hasten the establishment of peace.  Yet, at this very period, and while anxiously wishing this great object, he could not resist the desire for another campaign; one more exploit, to signalize the epoch at which he finally placed his sword in the scabbard.

Frederick Henry was essentially a soldier, with all the spirit of his race; and this evidence of the ruling passion, while he touched the verge of the grave, is one of the most striking points of his character.  He accordingly took the field; but, with a constitution broken by a lingering disease, he was little fitted to accomplish any feat worthy of his splendid reputation.  He failed in an attempt on Venlo, and another on Antwerp, and retired to The Hague, where for some months he rapidly declined.  On the 14th of March, 1647, he expired, in his sixty-third year; leaving behind