When Dante had passed through the third circle of the Inferno—­a desert of red-hot sand, in which lay a multitude of victims of divine wrath, additionally tortured by an ever-descending storm of fiery flakes—­he was led by Virgil out of this burning wilderness along a narrow causeway.  This path was protected, he said, against the showers of flame, by the lines of vapour which rose eternally from a boiling brook.  Even by such shadowy bulwarks, added the poet, do the Flemings between Kadzand and Bruges protect their land against the ever-threatening sea.

It was precisely among these slender dykes between Kadzand and Bruges that Alexander Farnese had now planted all the troops that he could muster in the field.  It was his determination to conquer the city of Sluys; for the possession of that important sea-port was necessary for him as a basis for the invasion of England, which now occupied all the thoughts of his sovereign and himself.

Exactly opposite the city was the island of Kadzand, once a fair and fertile territory, with a city and many flourishing villages upon its surface, but at that epoch diminished to a small dreary sand-bank by the encroachments of the ocean.

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.