But powerful as were the motives which stimulated Antwerp to resistance, equally strong were the reasons which determined the Spanish general to make himself master of the place at any cost. On the possession of this town depended in a great measure that of the whole province of Brabant, which by this channel chiefly derived its supplies of corn from Zealand, while the capture of this place would secure to the victor the command of the Scheldt. It would also deprive the league of Brabant, which held its meetings in the town, of its principal support; the whole faction of its dangerous influence, of its example, its counsels, and its money, while the treasures of its inhabitants would open plentiful supplies for the military exigencies of the king. Its fall would sooner or later necessarily draw after it that of all Brabant, and the preponderance of power in that quarter would decide the whole dispute in favor of the king. Determined by these grave considerations, the Duke of Parma drew his forces together in July, 1584, and advanced from his position at Dornick to the neighborhood of Antwerp, with the intention of investing it. But both the natural position and fortifications of the town appeared to defy attacks. Surrounded on the side of Brabant with insurmountable works and moats, and towards Flanders covered by the broad and rapid stream of the Scheldt, it could not be carried by storm; and to blockade a town of such extent seemed to require a land force three times larger than that which the duke had, and moreover a fleet, of which he was utterly destitute. Not only did the river yield the town all necessary supplies from Ghent, it also opened an easy communication with the bordering province of Zealand. For, as the tide of the North Sea extends far up the Scheldt, and ebbs and flows regularly, Antwerp enjoys the peculiar advantage that the same tide flows past it at different times in two opposite directions. Besides, the adjacent towns of Brussels, Malines, Ghent, Dendermonde, and others, were all at this time in the hands of the league, and could aid the place from the land side also. To blockade, therefore, the town by land, and to cut off its communication with Flanders and Brabant, required two different armies, one on each bank of the river. A sufficient fleet was likewise needed to guard the passage of the Scheldt, and to prevent all attempts at relief, which would most certainly be made from Zealand. But by the war which he had still to carry on in other quarters, and by the numerous garrisons which he was obliged to leave in the towns and fortified places, the army of the duke was reduced to ten thousand infantry and seventeen hundred horse, a force very inadequate for an undertaking of such magnitude. Moreover, these troops were deficient in the most necessary supplies, and the long arrears of pay had excited them to subdued murmurs, which hourly threatened to break out into open mutiny.