A stream of inland water, rising a few leagues to the south of Sluys, divided itself into many branches just before reaching the city, converted the surrounding territory into a miniature archipelago—­the islands of which were shifting treacherous sand-banks at low water, and submerged ones at flood—­and then widening and deepening into a considerable estuary, opened for the city a capacious harbour, and an excellent although intricate passage to the sea.  The city, which was well built and thriving, was so hidden in its labyrinth of canals and streamlets, that it seemed almost as difficult a matter to find Sluys as to conquer it.  It afforded safe harbour for five hundred large vessels; and its possession, therefore, was extremely important for Parma.  Besides these natural defences, the place was also protected by fortifications; which were as well constructed as the best of that period.  There was a strong rampire and many towers.  There was also a detached citadel of great strength, looking towards the sea, and there was a ravelin, called St. Anne’s, looking in the direction of Bruges.  A mere riband of dry land in that quarter was all of solid earth to be found in the environs of Sluys.

The city itself stood upon firm soil, but that soil had been hollowed into a vast system of subterranean magazines, not for warlike purposes, but for cellars, as Sluys had been from a remote period the great entrepot of foreign wines in the Netherlands.

While the eternal disputes between Leicester and the States were going on both in Holland and in England, while the secret negotiations between Alexander Farnese and Queen slowly proceeding at Brussels and Greenwich, the Duke, notwithstanding the destitute condition of his troops, and the famine which prevailed throughout the obedient Provinces, had succeeded in bringing a little army of five thousand foot, and something less than one thousand horse, into the field.  A portion of this force he placed under the command of the veteran La Motte.  That distinguished campaigner had assured the commander-in-chief that the reduction of the city would be an easy achievement.  Alexander soon declared that the enterprise was the most difficult one that he had ever undertaken.  Yet, two years before, he had carried to its triumphant conclusion the famous siege of Antwerp.  He stationed his own division upon the isle of Kadzand, and strengthened his camp by additionally fortifying those shadowy bulwarks, by which the island, since the age of Dante, had entrenched itself against the assaults of ocean.

On the other hand, La Motte, by the orders of his chief, had succeeded, after a sharp struggle, in carrying the fort of St. Anne.  A still more important step was the surprising of Blankenburg, a small fortified place on the coast, about midway between Ostend and Sluys, by which the sea-communications with the former city for the relief of the beleaguered town were interrupted.