Leyden was relieved by the desperate device of cutting the dykes and opening the sluices to flood the land around it. A fleet was thus enabled to sail in amidst fields and farmhouses to attack the besieging Spanish. The Sea-Beggars were driven by the wind to the outskirts of Leyden, where they engaged in mortal conflict. The forts fell into their hands, some being deserted by the Spanish who fled from the rising waters. William of Orange received the news at Delft, where he had taken up his residence. He founded the University of Leyden as a memorial of the citizens' endurance. The victory, however, was modified some months later by the capture of Zierickzee, which gave the Spaniards an outlet on the sea and also cut off Walcheren from Holland.
In sheer desperation William made overtures to Queen Elizabeth, offering her the sovereignty of Holland and Zealand if she would engage in the struggle against Spain. Elizabeth dared not refuse, lest France should step into the breach, but she was unwilling to declare herself publicly on the side of rebels.
In April 1576 an Act of Federation was signed which formally united the two States of Zealand and Holland and conferred the supreme authority on the Prince of Orange, commander in war and governor in peace. Requesens was dead; a general patriotic rising was imminent. On September 26th the States-General met at Brussels to discuss the question of uniting all the provinces.
The Spanish Fury at Antwerp caused general consternation in the Netherlands. The ancient town was attacked quite suddenly, all its wealth falling into the hands of rapacious soldiers. No less than 7000 citizens met their death at the hands of men who carried the standard of Christ on the Cross and knelt to ask God's blessing before they entered on the massacre! Greed for gold had come upon the Spaniards, who hastened to secure the treasures accumulated at Antwerp. Jewels and velvets and laces were coveted as much as the contents of the strong boxes of the merchants, and torture was employed to discover the plate and money that were hidden. A wedding-party was interrupted, and the clothes of the bride stripped from her. Many palaces fell by fire and the splendid Town House perished. For two whole days the city was the scene of indescribable horrors.
The Pacification of Ghent had been signed when the news of the Spanish Fury reached the States-General. The members of this united with the Prince of Orange, as ruler of Holland and Zealand, to drive the foreigner from their country. The Union of Brussels confirmed this treaty in January 1577, for the South were anxious to rid themselves of the Spaniards though they desired to maintain the Catholic religion. Don John of Austria, Philip II's half-brother, was accepted as Governor-General after he had given a general promise to observe the wishes of the people.
Don John made a state entry into Brussels, but he soon found that the Prince of Orange had gained complete ascendancy over the Netherlands and that he was by no means free to govern as he chose. Don John soon grew weary of a position of dependence; he seized Namur and took up his residence there, afterwards defying the States-General. A universal cry for Orange was raised in the confusion that followed, and William returned in triumph to the palace of Nassau. Both North and South demanded that he should be their leader; both Protestant and Catholic promised to regard his government as legal.
In January 1578, the Archduke Matthias, brother of the Emperor, was invited by the Catholic party to enter Brussels as its governor. William welcomed the intruder, knowing that the supreme power was still vested in himself, but he was dismayed to see Alexander of Parma join Don John, realizing that their combined armies would be more than a match for his. Confusion returned after a victory of Parma, who was an able and brilliant general. The Catholic Duke of Anjou took Mons, and John Casimir, brother of the Elector-Palatine, entered the Netherlands from the east as the champion of the extreme Calvinists.
The old religious antagonism was destroying the union of the provinces. William made immense exertions and succeeded in securing the alliance of Queen Elizabeth, Henry of Navarre, and John Casimir, while the Duke of Anjou accepted the title of Defender of the Liberties of the Netherlands. His work seemed undone on the death of Don John in 1578 and the succession of Alexander, Duke of Parma. This Prince sowed the seeds of discord very skilfully, separating the Walloon provinces from the Reformers. A party of Catholic Malcontents was formed in protest against the excesses of the Calvinists. Religious tolerance was to be found nowhere, save in the heart of William of Orange. North and South separated in January 1579, and made treaties which bound them respectively to protect their own form of religion.
Attempts were made to induce Orange to leave the Netherlands that Spain might recover her lost sovereignty. He was surrounded by foes, and many plots were formed against him. In March 1581, King Philip denounced him as the enemy of the human race, a traitor and a miscreant, and offered a heavy bribe to anyone who would take the life of "this pest" or deliver him dead or alive.
William's defence, known to the authorities as his Apology, was issued in every court of Europe. In it he dwelt on the different actions of his long career, and pointed out Philip's crimes and misdemeanours. His own Imperial descent was contrasted with the King of Spain's less illustrious ancestry, and an eloquent appeal to the people for whom he had made heroic sacrifices was signed by the motto Je le maintiendrai. ("I will maintain.")