When William of Orange was assassinated, he was succeeded as stadholder by his son Maurice. For a while, the provinces that had rebelled against Spain searched for a suitable sovereign, until in 1587 they decided to govern the country themselves. With Maurice as military leader, the Dutch Republic was able to profit from the international situation: the Spaniards were driven back south of the main rivers.
The assassination of rebel leader William of Orange could not have happened at a worse time. Campaigning from the south, the brilliant Spanish general, the Duke of Parma, quickly retook one town after another. Following Parma’s spectacular sack of Antwerp in 1585, the English under Queen Elizabeth I feared the rise of a powerful concentration of Spanish forces across the sea. The queen’s favourite, the Earl of Leicester, was sent with an army to the Low Countries to support the insurgents. But the English were divided and weak. In 1597, Leicester returned to England and left the Dutch to fend for themselves. The States of Holland, with Stadholder Maurice and Johan van Oldenbarnevelt at the helm as grand pensionary, played a key role in the new Dutch Republic. The military tide turned when in 1588, the English chased off the ostensibly invincible Spanish Armada. The much-feared Parma also disappeared from the scene: he was reassigned to lead a military expedition to France.
Maurice, and his Frisian cousin Willem Lodewijk, stadholder of Friesland, took advantage of the lack of Spanish opposition. Having modernised their army, they launched an offensive strategy that soon bore fruit. In 1590, they managed to surprise the fortified town of Breda with a ploy devised by a bargeman: he advised smuggling 75 soldiers into the citadel in a peat barge. Once inside, they overwhelmed the Spanish garrison and enabled Maurice to enter the town triumphant. This was soon followed by more victories at Coevorden, Steenwijk, Geertruidenberg and Groningen. The captured towns were restored to their previous position in their respective provinces. Not so for the territory captured in Zeeland-Flanders and Brabant. These areas came under direct rule by the States General and served as military buffer zones.
As Maurice swept to victory, troubles began to mount for the royalist southern provinces. Plagued by internal squabbling, mutinies and bankruptcy, in 1598 the Spanish king left the government of the Netherlands to his daughter Isabella and her husband, Archduke Albert. They had effectively lost the northern provinces. And northern insurgents were making inroads into the Archdukes’ own terrain. To counter the privateers operating from Dunkirk against Dutch merchants, the States of Holland and West Friesland proposed to invade Flanders. As commander of the army, Maurice was far from enthusiastic, yet he took charge, as ordered by the States General. While he won the battle on the beach at the harbour town of Nieuwpoort on 2 July 1600, the campaign in Flanders did not gain any territory for the Dutch. Moreover, casualties were high and the Dunkirk privateers remained as active as ever. On the other hand, the victory raised Maurice’s fame and prestige as a general to new heights.
Following the inconclusive campaign in Flanders, Maurice found himself facing another opponent of stature. The Spanish king had sent Ambrogio Spinola to the Netherlands to give the Archdukes military support. As commander he began by focusing on besieging Ostend, the last bastion of the rebels in the Catholic South. Since the Republic was able to continue supplying the city by sea, the siege continued for three full years. Almost 100,000 people died and the city was completely devastated. Finally, in 1604 Spinola managed to capture what was left of Ostend. Alarm then spread in the North as the Spanish army launched a successful campaign along the eastern border of the Republic: Spinola captured Oldenzaal, Lochem, Lingen, Rijnberk and Groenlo. Maurice attempted in vain to break the Spanish siege of the latter in 1606.
Skirmishing in the Republic’s border region represented no serious change in the balance of power between Spain and Holland. Yet at sea the Dutch were able to gain an advantage. In 1602, a combined fleet from Holland and England had attacked six large Spanish galleys that were patrolling between the Dutch and English coast. A more successful action occurred at Gibraltar in 1607, where an entire Spanish fleet of 21 ships was destroyed. A fleet commanded by Jacob van Heemskerk surprised the Spaniards in their home port. Van Heemskerck died in the battle. He was later given a hero’s funeral in his native Amsterdam. After the defeat at Gibraltar, intermediaries managed to persuade Spain to discuss terms for peace. Spinola even came to The Hague in person. In 1609, both parties agreed to a Twelve Year Truce.