While the Prince had been thus occupied in preparing the stout-hearted province for the last death-struggle with its foe, that mortal combat was already fast approaching; for the aspect of the contest in the Netherlands was not that of ordinary warfare. It was an encounter between two principles, in their nature so hostile to each other that the absolute destruction of one was the only, possible issue. As the fight went on, each individual combatant seemed inspired by direct personal malignity, and men found a pleasure in deeds of cruelty, from which generations not educated to slaughter recoil with horror. To murder defenceless prisoners; to drink, not metaphorically but literally, the heart's blood of an enemy; to exercise a devilish ingenuity in inventions of mutual torture, became not only a duty but a rapture. The Liberty of the Netherlands had now been hunted to its lair. It had taken its last refuge among the sands and thickets where its savage infancy had been nurtured, and had now prepared itself to crush its tormentor in a last embrace, or to die in the struggle. After the conclusion of the sack and massacre of Naarden, Don Frederic had hastened to Amsterdam, where the Duke was then quartered, that he might receive the paternal benediction for his well-accomplished work. The royal approbation was soon afterwards added to the applause of his parent, and the Duke was warmly congratulated in a letter written by Philip as soon as the murderous deed was known, that Don Frederic had so plainly shown himself to be his father's son. There was now more work for father and son. Amsterdam was the only point in Holland which held for Alva, and from that point it was determined to recover the whole province. The Prince of Orange was established in the southern district; Diedrich Sonoy, his lieutenant, was stationed in North Holland. The important city of Harlem lay between the two, at a spot where the whole breadth of the territory, from sea to sea, was less than an hour's walk. With the fall of that city the province would be cut in twain, the rebellious forces utterly dissevered, and all further resistance, it was thought, rendered impossible.