Next day he marched against the Salt, at a pass where fourteen hundred Spaniards were stationed.  Making very ostentatious preparations for an attack upon this position, he suddenly fell backwards down the stream to a point which he had discovered to be fordable at low water, and marched his whole army through the stream while the skirmishing was going on a few miles farther up.  The Spaniards, discovering their error, and fearing to be cut off, scampered hastily away to Dam.  Both streams were now in the control of the republican army, while the single fort of St. Joris was all that was now interposed between Maurice and the much-coveted Swint.  This redoubt, armed with nine guns, and provided with a competent, garrison, was surrendered on the 23rd May.

The Swint, or great sea-channel of Sluys, being now completely in the possession of the stadholder, he deliberately proceeded to lay out his lines, to make his entrenched camp, and to invest his city with the beautiful neatness which ever characterized his sieges.  A groan came from the learned Lipsius, as he looked from the orthodox shades of Louvain upon the progress of the heretic prince.

“Would that I were happier,” he cried, “but things are not going on in Flanders as I could wish.  How easy it would have been to save Sluys, which we are now trying so hard to do, had we turned our attention thither in time!  But now we have permitted the enemy to entrench and fortify himself, and we are the less excusable because we know to our cost how felicitously he fights with the spade, and that he builds works like an ancient Roman. . . .  Should we lose Sluys, which God forbid, how much strength and encouragement will be acquired by the foe, and by all who secretly or openly favour him!  Our neighbours are all straining their eyes, as from a watch-tower, eager to see the result of all these doings.  But what if they too should begin to move?  Where should we be?  I pray God to have mercy on the Netherlanders, whom He has been so many years chastising with heavy whips.”

It was very true.  The man with the spade had been allowed to work too long at his felicitous vocation.  There had been a successful effort made to introduce reinforcements to the garrison.  Troops, to the number of fifteen hundred, had been added to those already shut up there, but the attempts to send in supplies were not so fortunate.  Maurice had completely invested the town before the end of May, having undisputed possession of the harbour and of all the neighbouring country.  He was himself encamped on the west side of the Swint; Charles van der Noot lying on the south.  The submerged meadows, stretching all around in the vicinity of the haven, he had planted thickly with gunboats.  Scarcely a bird or a fish could go into or out of the place.  Thus the stadholder exhibited to the Spaniards who, fifteen miles off towards the west, had been pounding and burrowing three years long before Ostend without success, what he understood by a siege.