During the course of the year other severe misfortunes had happened to the states.  Treachery, even among the men who had done good service to the cause of freedom, was daily showing her hateful visage.  Not only the great chieftains who had led the Malcontent Walloon party, with the fickle Aerschot and the wavering Havre besides, had made their separate reconciliation with Parma, but the epidemic treason had mastered such bold partisans as the Seigneur de Bours, the man whose services in rescuing the citadel of Antwerp had been so courageous and valuable.  He was governor of Mechlin; Count Renneberg was governor of Friesland.  Both were trusted implicitly by Orange and by the estates; both were on the eve of repaying the confidence reposed in them by the most venal treason.

It was already known that Parma had tampered with De Bours; but Renneberg was still unsuspected.  “The Prince,” wrote Count John, “is deserted by all the noblemen; save the stadholder of Friesland and myself, and has no man else in whom he can repose confidence.”  The brothers were doomed to be rudely awakened from the repose with regard to Renneberg, but previously the treason of a less important functionary was to cause a considerable but less lasting injury to the national party.

In Mechlin was a Carmelite friar, of audacious character and great eloquence; a man who, “with his sweet, poisonous tongue, could ever persuade the people to do his bidding.”  This dangerous monk, Peter Lupus, or Peter Wolf, by name, had formed the design of restoring Mechlin to the Prince of Parma, and of obtaining the bishopric of Namur as the reward of his services.  To this end he had obtained a complete mastery over the intellect of the bold but unprincipled De Bours.  A correspondence was immediately opened between Parma and the governor, and troops were secretly admitted into the city.  The Prince of Orange, in the name of the Archduke and the estates, in vain endeavoured to recal the infatuated governor to his duty.  In vain he conjured him, by letter after letter, to be true to his own bright fame so nobly earned.  An old friend of De Bours, and like himself a Catholic, was also employed to remonstrate with him.  This gentleman, De Fromont by name, wrote him many letters; but De Bours expressed his surprise that Fromont, whom he had always considered a good Catholic and a virtuous gentleman, should wish to force him into a connection with the Prince of Orange and his heretic supporters.  He protested that his mind was quite made up, and that he had been guaranteed by Parma not only the post which he now held, but even still farther advancement.