Requesens had been long revolving in his mind the means of possessing himself of this important, island.  He had caused to be constructed, a numerous armada of boats and light vessels of various dimensions, and he now came to Tholew to organize the expedition.  His prospects were at first not flattering, for the gulfs and estuaries swarmed with Zealand vessels, manned by crews celebrated for their skill and audacity.  Traitors, however, from Zealand itself now came forward to teach the Spanish Commander how to strike at the heart of their own country.  These refugees explained to Requesens that a narrow flat extended under the sea from Philipsland, a small and uninhabited islet situate close to Tholen, as far as the shore of Duiveland.  Upon this submerged tongue of land the water, during ebb-tide, was sufficiently shallow to be waded, and it would therefore be possible for a determined band, under cover of the night, to make the perilous passage.  Once arrived at Duiveland, they could more easily cross the intervening creek to Schouwen, which was not so deep and only half as wide, so that a force thus, sent through these dangerous shallows, might take possession of Duiveland and lay siege to Zierickzee, in the very teeth of the Zealand fleet, which would be unable to sail near enough to intercept their passage.

The Commander determined that the enterprise should be attempted.  It was not a novelty, because Mondragon, as we have seen, had already most brilliantly conducted a very similar expedition.  The present was, however, a much more daring scheme.  The other exploit, although sufficiently hazardous, and entirely, successful, had been a victory gained over the sea alone.  It had been a surprise, and had been effected without any opposition from human enemies.  Here, however, they were to deal, not only with the ocean and darkness, but with a watchful and determined foe.  The Zealanders were aware that the enterprise was in contemplation, and their vessels lay about the contiguous waters in considerable force.  Nevertheless, the determination of the Grand Commander was hailed with enthusiasm by his troops.  Having satisfied himself by personal experiment that the enterprise was possible, and that therefore his brave soldiers could accomplish it, he decided that the glory of the achievement should be fairly shared, as before, among the different nations which served the King.

After completing his preparations, Requesens came to Tholen, at which rendezvous were assembled three thousand infantry, partly Spaniards, partly Germans, partly Walloons.  Besides these, a picked corps of two hundred sappers and miners was to accompany the expedition, in order that no time might be lost in fortifying themselves as soon as they had seized possession of Schouwen.  Four hundred mounted troopers were, moreover, stationed in the town of Tholen, while the little fleet, which had been prepared at Antwerp; lay near that city ready to co-operate with the land