CHAPTER X. FROM THE END OF THE TWELVE YEARS' TRUCE TO THE PEACE OF MUENSTER (1621-48). THE STADHOLDERATE OF FREDERICK HENRY OF ORANGE
In the autumn of this year, 1643, two special envoys were sent by Cardinal Mazarin to the Hague; and one of the results of their visit was a renewal of the treaty of 1635 by which France and the United Provinces had entered upon an offensive and defensive alliance and had agreed to conclude no peace but by mutual consent. Nevertheless Frederick Henry, whom long experience had made wary and far-sighted, had been growing for some little time suspicious of the advantage to the republic of furthering French aggrandisement in the southern Netherlands. He saw that France was a waxing, Spain a waning power, and he had no desire to see France in possession of territory bordering on the United Provinces. This feeling on his part was possibly the cause of the somewhat dilatory character of his military operations in 1641 and 1642. The revolt of Portugal from Spain in December, 1640, had at first been welcomed by the Dutch, but not for long. The great and successful operations of the East and West India Companies had been chiefly carried on at the expense of the Portuguese, not of the Spaniards. The great obstacle to peace with Spain had been the concession of the right to trade in the Indies. It was Portugal, rather than Spain, which now stood in the way of the Dutch merchants obtaining that right, for the Spanish government, in its eagerness to stamp out a rebellion which had spread from the Peninsula to all the Portuguese colonies, was quite ready to sacrifice these to secure Dutch neutrality in Europe. The dazzling victory of the French under the young Duke of Enghien over a veteran Spanish army at Rocroi (May, 1643) also had its effect upon the mind of the prince. With prophetic foresight, he rightly dreaded a France too decisively victorious. In the negotiations for a general peace between all the contending powers in the Thirty Years' War, which dragged on their slow length from 1643 to 1648, the stadholder became more and more convinced that it was in the interest of the Dutch to maintain Spain as a counterpoise to the growing power of France, and to secure the favourable terms, which, in her extremity, Spain would be ready to offer.
At first, however, there was no breach in the close relations with France; and Frederick Henry, though hampered by ill-health, showed in his last campaigns all his old skill in siege-craft. By the successive captures of Hertogenbosch, Maestricht and Breda he had secured the frontiers of the republic in the south and south-east. He now turned to the north-west corner of Flanders. In 1644 he took the strongly fortified post of Sas-van-Gent, situated on the Ley, the canalised river connecting Ghent with the Scheldt. In 1645 he laid siege to and captured the town of Hulst, and thus gained complete possession of the strip of territory south of the Scheldt, known as the Land of Waes, which had been protected by these two strongholds, and which has since been called Dutch Flanders.
Very shortly after the capitulation of Hulst, the ambassadors plenipotentiary of the United Provinces set out (November, 1645) to take their places at the Congress of Muenster on equal terms with the representatives of the Emperor and of the Kings of France and Spain. The position acquired by the Dutch republic among the powers of Europe was thus officially recognised de facto even before its independence had been de jure ratified by treaty. The parleyings at Muenster made slow headway, as so many thorny questions had to be settled. Meanwhile, with the full approval of the prince, negotiations were being secretly carried on between Madrid and the Hague with the view of arriving at a separate understanding, in spite of the explicit terms of the treaty of 1635. As soon as the French became aware of what was going on, they naturally protested and did their utmost to raise every difficulty to prevent a treaty being concluded behind their backs. The old questions which had proved such serious obstacles in the negotiations of 1607-9 were still sufficiently formidable. But the situation was very different in 1646-7. The Spanish monarchy was actually in extremis. Portugal and Catalonia were in revolt; a French army had crossed the Pyrenees; the treasury was exhausted. Peace with the Dutch Republic was a necessity; and, as has been already said, the vexed question about the Indies had resolved itself rather into a Portuguese than a Spanish question. By a recognition of the Dutch conquests in Brazil and in the Indian Ocean they were acquiring an ally without losing anything that they had not lost already by the Portuguese declaration of independence. But, as the basis of an agreement was on the point of being reached, an event happened which caused a delay in the proceedings.