Zúñiga, however, had been right: the electoral transfer provoked an enormous outcry, for it was clearly unconstitutional. The Golden Bull of 1356, which was universally regarded in Germany as the fundamental and immutable law of the empire, ordained that the electorate should remain in the Palatine house in perpetuity. The transfer of 1623 thus undermined a cornerstone of the Constitution, which many regarded as their only true safeguard against absolute rule. Inside Germany, a pamphlet war against Maximilian and Ferdinand began; outside, sympathy for Frederick at last created that international body of support for his cause which had previously been so conspicuously lacking. The Dutch and the Palatine exiles found little difficulty in engineering an alliance involving France, England, Savoy, Sweden, and Denmark that was dedicated to the restoration of Frederick to his forfeited lands and titles (the Hague Alliance, Dec. 9, 1624). Its leader was Christian IV of Denmark (1588–1648), one of the richest rulers in Christendom, who saw a chance to extend his influence in northern Germany under cover of defending “the Protestant cause.” He invaded the empire in June 1625.
The Protestants’ diplomatic campaign had not gone unnoticed, however. Maximilian’s field commander, Count Tilly, warned that his forces alone would be no match for a coalition army and asked that the emperor send reinforcements. Ferdinand obliged: in the spring of 1625 he authorized Albrecht von Wallenstein, military governor of Prague, to raise an imperial army of 25,000 men and to move it northward to meet the Danish threat. Wallenstein’s approach forced Christian to withdraw; when the Danes invaded again the following year, they were routed at the Battle of Lutter (Aug. 26, 1626). The joint armies of Tilly and Wallenstein pursued the defeated forces: first they occupied the lands of North German rulers who had declared support for the invasion, then they conquered the Danish mainland itself. Christian made peace in 1629, promising never again to intervene in the empire. His allies had long since withdrawn from the struggle.
The White Mountain delivered the Bohemian rebels into the emperor’s grasp; Lutter delivered the rebels’ German supporters. After the victories, important new policies were initiated by Ferdinand which aimed at exalting the Catholic religion and his own authority. In the Habsburg provinces there was widespread confiscation of land—perhaps two-thirds of the kingdom of Bohemia changed hands during the 1620s—and a new class of loyal landowners—like Wallenstein—was established. At the same time, the power of the Estates was curtailed and freedom of worship for Protestants was restricted (in some territories) or abolished (in most of the rest). Even a rebellion in Upper Austria in 1626, provoked principally by the persecution of Protestants, failed to change Ferdinand’s mind. Indeed, fortified by his success in the Habsburg lands, he decided to implement new policies in the empire. First, disloyal rulers were replaced (the Palatinate went to Maximilian, Mecklenburg to Wallenstein, and so on). Next, serious steps were taken to reclaim church lands that had fallen into Protestant hands. At first this was done on a piecemeal basis, but on March 28, 1629, an Edict of Restitution was issued which declared unilaterally that all church lands secularized since 1552 must be returned at once, that Calvinism was an illegal creed in the empire, and that ecclesiastical princes had the same right as secular ones to insist that their subjects should be of the same religion as their ruler. The last clause, at least, was clearly contrary to the terms of the Peace of Augsburg, which Protestants regarded as a central pillar of the Constitution. There was, however, no opportunity for argument, for the imperial edict was enforced immediately, brutally, by the armies of Wallenstein and Tilly, which now numbered some 200,000 men. The people of the empire seemed threatened with an arbitrary rule against which they had no defense. It was this fear, skillfully exploited once again by Protestant propagandists, which ensured that the war in Germany did not end in 1629 with the defeat of Denmark. Ferdinand may have won numerous military victories, but in doing so he had suffered a serious political defeat. The pens of his enemies proved mightier than the sword. The crisis of the war, 1629–35
If Maximilian of Bavaria desired the title of elector as his reward for supporting Ferdinand, Spain (for its part) required imperial support for its war against the Dutch. When repeated requests for a direct invasion by Wallenstein’s army remained unanswered (largely due to Bavarian opposition), Spain began to think of creating a Baltic navy, with imperial assistance, which would cleanse the inland sea of Dutch shipping and thus administer a body blow to the republic’s economy. But the plan aborted, for the imperial army failed in 1628 to conquer the port of Stralsund, selected as the base for the new fleet. Now, with Denmark defeated, Madrid again pleaded for the loan of an imperial army, and this time the request was granted. In the end, however, the troops did not march to the Netherlands: instead, they went to Italy.
The death of the last native ruler of the strategic states of Mantua and Montferrat in December 1627 created dangers in Italy that the Spaniards were unable to ignore and temptations that they were unable to resist. Hoping to forestall intervention by others, Spanish forces from Lombardy launched an invasion, but the garrisons of Mantua and Montferrat declared for the late duke’s relative, the French-born duke of Nevers. Nevers lacked the resources to withstand the forces of Spain alone, and he appealed to France for support. Louis XIII (1610–43) and Cardinal Richelieu (chief minister 1624–42) were, however, engaged in a desperate war against their Calvinist subjects; only when the rebels had been defeated, early in 1629, was it possible for the king and his chief minister to cross the Mount Cenis Pass and enter Italy. It was to meet this threat that the emperor was asked by Philip IV of Spain (1621–65) to send his troops to Italy rather than to the Netherlands. When Louis XIII launched a second invasion in 1630, some 50,000 imperial troops were brought south to oppose them, reducing the war for Mantua to a stalemate but delivering the Dutch Republic from immediate danger and weakening the emperor’s hold on Germany.
Gustav II Adolf of Sweden (1611–32) had spent most of the 1620s at war with Poland, seeking to acquire territory on the southern shore of the Baltic. By the Truce of Altmark (Sept. 26, 1629), with the aid of French and British mediators, Poland made numerous concessions in return for a six-year truce. Gustav lost no time in redeploying his forces: on July 6, 1630, he led a Swedish expeditionary force ashore near Stralsund with the declared intention of saving the “liberties of the empire” and preserving the security of the Baltic.
Despite the defeat of the German Protestants and their allies, Sweden’s position was far more favourable than that of Denmark five years earlier. Instead of the two armies that had faced Christian IV, Gustav was opposed by only one, for in the summer of 1630 the emperor’s Catholic allies in Germany—led by Maximilian of Bavaria—demanded the dismissal of Wallenstein and the drastic reduction of his expensive army. It was an ultimatum that Ferdinand, with the bulk of his forces tied down in the war of Mantua, could not ignore, even though he thereby lost the services of the one man who might conceivably have retained all the imperial gains of the previous decade and united Germany under a strong monarchy.