Spain in the Thirty Years’ War

The Surrender of Breda by Velázquez, painted by order of King Philip IV of Spain, 1635, five years after the loyal Ambrosio Spínola died as Governor of Milan. Spinola magnanimously raises the surrendering governor of Breda. Museum of Prado, Madrid, Spain.

As the Twelve Years’ Truce approached its end, it became obvious that the Spanish empire needed a new strategy. By 1618, Europe was drifting into the generalized crisis that became the Thirty Years’ War. The Dutch truce had proved so harmful to Spain that few observers thought the king would renew it without major concessions. While Antwerp suffered under a de facto commercial blockade, the Dutch had made serious inroads against the Portuguese empire in Asia and had greatly expanded their activities in the Caribbean. The Portuguese asked how Spanish rule could be justified if the king did not protect them against their commercial rivals. The Council of Indies complained of Dutch inroads in America, while the Council of Finance pointed out that the cost of maintaining the Army of Flanders would be little greater if its soldiers actually fought. All three bodies therefore opposed continuation of the truce.

The Duke of Lerma fell from power in the midst of this debate, albeit for reasons that had little to do with foreign policy. He was replaced by Don Baltasar de Zúñiga, an experienced diplomat who agreed that the existing agreement was untenable and thought that the international situation now favored Spain. England had been a de facto ally since 1605, while the assassination of Henry IV in 1610 had left France under a weak regency that seemed incapable of developing a consistent foreign policy. Neither would intervene to help the Dutch as they had done in the past. The Dutch, too, had become more belligerent. In August, 1618, Maurice of Nassau and the more extreme Calvinists triumphed over a moderate faction led by Johan van Oldenbarnevelt. Although more isolated than ever, the new regime was unlikely to concede anything to Spain.

While Spain and the Dutch debated the merits of the truce, tensions in the Holy Roman Empire reached dangerous levels. Confessional differences had been growing since the 1580s, in part because of the emergence of Calvinism as a major force in German politics. After the Imperial Diet of 1608, both Protestant and Catholic princes created formal unions that sought alliances with non-German powers. The Protestant Union in particular had signed treaties with England in 1612 and with the United Provinces in 1613. By 1618, the old and childless emperor Matthias neared death. His nephew, the devoutly catholic Ferdinand of Styria, was expected to succeed him and had already been designated king-elect of Bohemia by the Bohemian Diet, most of whose members were Protestant. Then, on May 28, a long-simmering dispute over the reversion of ecclesiastical properties prompted the Bohemian Protestants to revolt. Their representatives in the Diet threw two of Ferdinand’s regents from a third-story window (the Defenestration of Prague) and set up a provisional government. In the course of the summer, three other Habsburg territories, Lusatia, Silesia, and Upper Austria joined the Bohemians and began the search for a new king. The Protestant Union pledged its support, and in May, 1619, its armies besieged Vienna.

To Zúñiga and his allies at the Spanish court, these actions threatened the survival of the Habsburg dynasty. Of the seven imperial electors, three were already Protestant. If the Bohemians elected a Protestant as they promised to do, the Catholics would be in a minority and sooner or later the Holy Roman Empire would fall into Protestant hands. Over the protests of Lerma’s remaining supporters, Zúñiga convinced the king to abort an attack on Algiers and divert the money to Austria together with 7000 Spaniards from the army of Flanders. By this time Ferdinand had raised an army of his own. The Protestant siege of Vienna collapsed in June, but Moravia and Lower Austria joined the revolt, and on August 22, the expanded confederation offered the crown of Bohemia to Frederick, Count Palatine of the Rhine. Frederick was a firm Calvinist and already an elector in his own right. He was also the son-in-law of James I of England and Scotland. If he survived, he would have two votes out of seven in the Electoral College. The emperor Matthias had died in March and Ferdinand now moved quickly to secure the imperial office before Frederick could be confirmed as King of Bohemia. The electors, unaware of events in Bohemia, duly pronounced him Emperor Ferdinand II on August 28.

In the fall of 1619, Spanish policy moved decisively toward open war. The prospect of a Holy Roman Empire dominated by Calvinists and allied with the Dutch was intolerable. Oñate, the Spanish ambassador to Vienna, helped Ferdinand reactivate the empire’s Catholic League by offering the Upper Palatinate to Maximilian of Bavaria if Frederick were defeated. James of England, influenced in part by Spanish diplomacy, refused to support his son-in-law, and Spanish agents at the Turkish court convinced the sultan to drop his support for Bethlen Gabor, the Calvinist ruler of Transylvania who had conquered Habsburg Hungary in November. By the following spring, Frederick’s support in the Protestant Union had dwindled as the Lutheran princes withdrew their support. They were beginning to fear Calvinists more than Catholics. Genoa, Tuscany, and the pope added to the 3.4 million reichsthalers already provided by the Spanish, and the stage was set for a Calvinist disaster.

In July, 1620, an imperial army invaded Upper Austria, while the Saxons marched into Lusatia. Finally on November 8, Frederick and the Bohemians went down to final defeat at the battle of the White Mountain. The immediate crisis ended, but Spain had not been idle. A detachment of 20,000 men from the army of Flanders occupied the Lower Palatinate, depriving Frederick of his homeland and securing Spanish control over the Rhine. A new Spanish Road that connected Italy with the Netherlands through the Rhineland was now secure. Meanwhile, Spanish and Imperial troops resolved the ongoing struggle for the Valtelline, the upper valley of the Adda that connects Lake Como to the valley of the Inn. The Valtelline had long been ruled by the Protestants of the Grisons. Its Catholic inhabitants rebelled in 1572, 1607, and 1618. In 1620, the Spanish and Austrians sealed off both ends of the valley, allowing the Catholics to rise up and kill the Protestants. The Spanish route from Milan to Austria was now secure as well.

When the Twelve Years’ Truce expired on April 21, 1621, a new Spanish strategy was firmly in place. Philip III had died in March of the same year, leaving the government in the hands of Philip IV, aged 16, and Zúñiga. Archduke Albert died at Brussels in July. Zúñiga, who was old enough to have fought in the Armada of 1588, died in 1622, but his nephew, the Count (later Count-Duke) of Olivares succeeded him as valido and expanded upon his policies for the next 21 years. Gaspar de Guzmán, Count of Olivares, possessed inexhaustible energy. He also understood, perhaps better than most, that Spain’s imperial and foreign policy was in the long run unsustainable for economic reasons, but in light of recent experience the one thing Olivares could not do was avoid war.

The strategy he inherited from his predecessors centered on alliance with Austria, control of northern Italy, and war with the Dutch. It would embroil Spain in almost every aspect of the Thirty Years’ War and, eventually, in a disastrous confrontation with France. Few now believed that the Dutch provinces could be recovered, but Spanish policy makers still wanted to limit their depredations overseas and their ability to support the Protestant cause in Europe. Between 1621 and 1626 Olivares therefore tried to strike at the heart of the Dutch economy. The Republic had prospered by serving as an entrepot between inland Europe and the Atlantic world. Cloths and manufactured goods from Germany reached the markets of Amsterdam by way of the great rivers. Grain, timber, and naval stores from the Baltic were traded there as well, and transshipped to Spain and the Mediterranean. In what seemed an intolerable irony, Spain’s European empire had in the process become largely dependent upon goods imported from its Dutch enemies. Olivares rebuilt the Spanish fleet, which had been sadly neglected under Philip III, and established a squadron of 70 ships at Dunkirk to disrupt the Channel trade. He then worked with imperial forces to secure a Spanish base in the Baltic and set the army of Flanders to secure the inland water routes between Holland and Germany—all without sacrificing the Spanish armies in Italy.

The new strategy achieved early success. In 1625, the best year for Spanish arms in decades, Ambrogio Spínola, the brilliant Genoese commander of the Army of Flanders, took the strategically important Dutch fortress at Breda. Genoa was rescued from a joint attack by France and Savoy, and a Spanish fleet recaptured the Brazilian city of Bahía from a Dutch expedition that had seized it in May of 1624. In England, Charles I succeeded his father, James, and launched a farcical attack on Cádiz in retaliation for his failure to arrange a marriage with Philip IV’s sister, Maria, but fortunately for Spain, England’s military capabilities had degenerated since the days of Elizabeth I. It looked for a time as though Spain was about to revive its ancient glories, but by 1628 the Count-Duke’s strategy was in tatters. The failure arose in part from the fortunes of war, but its primary cause was that the Spanish empire no longer possessed the resources to achieve its strategic ends.

War with France

The failure to reform its economy left the empire ill-equipped for the struggles to come. From 1623 to 1627 imperial strategy had achieved a fair measure of success despite the endless problems of finance. By 1628, however, the crown was 2 million ducats short of the funds needed for the years’ campaigns. Then, in September, the Dutch admiral Piet Heyn caught the treasure fleet from New Spain at anchor in Matanzas Bay, Cuba, and seized its treasure. The captured bullion enabled the Dutch to launch a new offensive against the Army of Flanders. In another military reversal, Spain’s hope of a base in the Baltic died when the imperial general Wallenstein failed to take Stralsund. More significant in the long run was the development of a new Mantuan war that drained Spanish resources. Yet another dynastic crisis gave Mantua and Montferrat to the duke of Nevers, a member of the French branch of the Gonzaga family. To protect Milan, Olivares ordered a siege of the almost impregnable fortress of Casale, hoping that the French would be too preoccupied with their own siege of rebellious Huguenots at La Rochelle to intervene. La Rochelle, however, surrendered at the end of 1628, and in 1629, Louis XIII invaded Italy and forced the Spanish to abandon the siege. The Mantuan War ground on for another two years, but by then Spain’s attention had turned to a new threat in the north. Swedish intervention on behalf of the German Protestants emboldened the Dutch to seize a number of towns along the water line, the most important of which was Maastricht, which fell on August 23, 1632. Spain had to detach troops from its defense of the Palatinate against the Swedes, but the death of King Gustavus Adolfus at Lützen in November blunted the Swedish offensive. A series of imperial successes beginning with the capture of Breisach in 1633 and culminating in the victory over the Swedes at Nördlingen on September 6, 1634, convinced the Lutheran princes to sign the Peace of Prague (May 30, 1635) and to join with the emperor in hunting down those Calvinists who still refused to abandon the Swedish alliance.

At this point France declared war on Spain. The French government had emerged from the problems of Louis XIII’s regency, and since 1624, had fallen increasingly under the influence of Louis’s chief minister, Cardinal Richelieu. Richelieu and the king were determined to oppose what they saw as a Habsburg consortium that surrounded them on two sides. After the defeat of the Huguenots at La Rochelle, they felt free to adopt a more aggressive policy. Its first objectives were to secure their eastern borders by neutralizing Savoy (hence the Mantuan War) and Lorraine, and by enforcing a French protectorate over Alsace. Spanish distraction during the Swedish intervention had helped them to achieve these goals. Richelieu had also supported the Swedes with large infusions of cash. Now the Peace of Prague confronted France with the prospect of a united empire allied with Spain and unmolested by northern invaders. Louis and Richelieu had no desire to become involved in the military quagmire of central Europe, but thought that if Spain could be defeated, the Austrian Habsburgs would cease to be a threat. The French army, however, lacked the training and experience built up by Spain over more than a century of warfare. The army of Flanders easily defeated a Franco-Dutch invasion of the Spanish Netherlands, and in 1637 invaded France, advancing to within 80 miles of Paris. Had a planned invasion of Languedoc taken place at the same time, France might have been forced to make peace. But time was running out for Spain.

The next campaign season brought a French counterattack on Fuenterrabía, the great fortress that guarded the western flank of the Pyrennees. The siege failed, but far away in Germany, the French army managed to retake Breisach after a long siege. France already controlled Alsace, Lorraine, and Savoy. With the loss of Breisach, Spain’s land route to the Netherlands—long threatened—was now closed. Only by establishing naval superiority in the Channel and North Sea could Spain maintain communications with Brussels and supply the Army of Flanders. In 1639, Olivares decided to mount a new offensive by sea. His government had rebuilt the fleet, and now had 24 ships at Cádiz and 63 at Corunna. Others from Naples and Cantabria brought the total force up to the level of the 1588 Armada, although the new fleet carried more guns. He ordered its commander to clear the Biscayan Coast of French marauders before destroying the Dutch fleet in the Channel. Spanish diplomacy had neutralized the England of Charles I, and for once, the weather cooperated. The Dutch, unfortunately did not. After making contact with a Dutch squadron in September, the Spanish took refuge in the Downs, a broad anchorage off the English coast near Deal. There, on December 21, the Dutch destroyed most of the Spanish fleet.