Thirty Years War 1618–48

the first general European conflict involving two large groups of powers: on one side, the Hapsburg bloc—consisting of the Hapsburgs of Austria and Spain and supported by the Papal States, the Catholic princes of Germany, and the Polish-Lithuanian Commonwealth (Rzecz-pospolita)—which sought to attain domination over the entire Christian world; on the other side, a coalition of nation-states—composed of France, Sweden, the Republic of the United Provinces (the northern Netherlands), Denmark, Russia, and, adjunctly, England—which espoused the cause of the German Protestant princes and the anti-Hapsburg movements in Bohemia, Transylvania (Gábor Bethlen’s movement of 1619–26), and Italy. Although the war began as a religious conflict, it gradually lost its religious character, especially after Catholic France assumed the leadership of the anti-Hapsburg coalition.

The Thirty Years’ War was a reflection on the international level of the profound social and political disturbances, manifested in the outbreak of local revolutionary movements, that attended the emergence of capitalism in feudal Europe during the transition from the Middle Ages to the modern era. The Hapsburgs, representing the forces of reaction, endeavored to preserve Europe’s moribund feudal system.

Beginning in the late 16th century, a rapprochement between the Austrian and Spanish branches of the Hapsburg house provoked fears in Europe that a union of the two would lead to the restoration of the empire of Charles V. The first to oppose the Hapsburgs’ plans for supremacy on the Continent were the Protestant princes of Germany, whose independence within the Holy Roman Empire had been guaranteed by the Peace of Augsburg in 1555. When Emperor Rudolf II, therefore, inaugurated a campaign against the privileges of the Protestants, the German Protestant princes, in an effort to safeguard their independence and to retain the lands they had seized during the Reformation, formed a Protestant Union in 1608. The Protestant Union received the support of the feudal absolutist states, such as France and England, which perceived in the Hapsburgs’ plans a potential threat to their own interests. Soon after, the Catholic princes of Germany formed their own alliance—the Catholic League of 1609—with the backing of Spain and the Papal States.

In 1617 and 1618 the Hapsburgs attempted to circumscribe the privileges of Bohemia, which still retained a measure of independence under the Hapsburg monarchy. The Hapsburgs’ move precipitated the Bohemian Revolt of 1618–20, which became the focus of the general conflict in Europe and heralded the first phase of the Thirty Years’ War—the Bohemian, or Bohemian-Palatine, period (1618–23). In 1619 the leader of the Protestant Union, Frederick V of the Palatinate, was elected king of Bohemia, and in October of that year Emperor Ferdinand II concluded an alliance with the Catholic League. With military assistance from the Catholic League, Ferdinand attacked the forces of the Bohemian Protestants, completely defeating them in a major battle at Bílá Hora on Nov. 8, 1620. The early fall of Bohemia gave the advantage to the Hapsburg Catholic camp. In 1621 troops from the Catholic League and from Spain, under the command of A. Spinola, marched into the Palatinate and occupied it until 1623.

The second phase of the Thirty Years’ War, called the Danish period because of Denmark’s entrance into the war against the Hapsburgs, lasted from 1625 until 1629. In joining the conflict, Denmark acted, in effect, as a surrogate of France, England, and the United Provinces—which had formed an alliance in 1624—agreeing to carry out their political designs in return for large subsidies promised in the Treaty of The Hague, signed in December 1625. Yet Denmark, a Protestant country, had another reason for entering the war: it hoped to acquire territories on the southern Baltic coast. With the United Provinces’ main forces dispatched to Spain—where fighting had resumed in 1621 after the expiration of the Twelve Years’ Truce of 1609—the French government, headed since 1624 by Cardinal Richelieu, sought to maneuver both Denmark and Sweden, under King Gustavus II Adolphus, into the war in an effort to force the imperial army to fight on two fronts. Before the French plan could be effected, however, a war broke out in northeastern Europe between Sweden and the Polish-Lithuanian Commonwealth. The latter, closely linked with the Hapsburgs and facing both Sweden and Russia, served as the eastern outpost of the camp of Catholic reaction.

The Peasant War of 1626 in Upper Austria, and a concomitant upsurge in the peasant movement in Bohemia and elsewhere, greatly complicated the Hapsburgs’ situation. Nevertheless, imperial troops under A. Wallenstein and Catholic League troops under J. Tilly succeeded in inflicting a series of shattering defeats on the military forces of the anti-Hapsburg coalition: Wallenstein against E. Mansfeld, the commander of the coalition army, at Dessau on Apr. 25, 1626, and Tilly against Christian IV of Denmark at Lutter on Aug. 27,1626. By 1628 the Danish troops had been driven completely out of Germany; northern Germany was then occupied by Wallenstein, who immediately ordered the construction of a large German fleet for an invasion of the Danish islands. Thus threatened, Denmark sued for peace, and in May 1629 it signed the Treaty of Lübeck, which called for Denmark’s withdrawal from the conflict and for the restoration of prewar conditions. The military victories of the Catholic camp during this period of the Thirty Years’ War, accompanied as they were by the triumph of Catholic reaction in Germany, allowed the emperor to issue the Edict of Restitution in 1629.

Between 1628 and 1631, during the War for the Mantuan Succession (which some scholars treat as a separate period of the Thirty Years’ War), engagements were fought in northern Italy by Hapsburg and French troops. Yet Richelieu remained reluctant to commit France to a major war in Germany as long as the Holy Roman Empire was not engaged on two fronts. Sweden, meanwhile, having concluded the Altmark Truce of 1629 with the Polish-Lithuanian Commonwealth as a result of French, English, and Dutch mediation, was free to deploy its forces against the Hapsburgs. The grand strategy of the anti-Hapsburg coalition also envisioned armed action against the Polish-Lithuanian Commonwealth by Russia, which hoped to regain Smolensk and other Russian lands seized by Polish interventionists in the early 17th century. The object was to pin down the Commonwealth’s forces in the east.

In July 1630, Gustavus Adolphus invaded northern Germany, thereby opening the Swedish period (1630–35) of the Thirty Years’ War. In the summer of 1631 he marched into the interior of Germany at the head of a well-trained army. To help finance his campaign, the Swedish king used subsidies obtained from France, under the Treaty of Bärwalde in January 1631, and from Russia, in the form of grain sold to Sweden on highly favorable terms. Gustavus Adolphus’ participation in the war marked a new phase in Sweden’s struggle for supremacy in the Baltic. The German peasants, as well as some burghers, greeted Gustavus Adolphus and his troops, mostly free Swedish peasants, as liberators from the oppression of the imperial princes and nobles. The German Protestants consequently pinned all their hopes on the Swedish king. Gustavus Adolphus, however, exploited his victories, made easier because of German popular support, to effect a deal with the princes in an attempt to place the empire under his rule.

On Sept. 17,1631, Gustavus Adolphus defeated Tilly’s army at Breitenfeld, near Leipzig. He then moved out across Germany, and in May 1632 he captured the Bavarian capital of Munich, posing a direct threat to the Austrian lands of the Hapsburgs. Meanwhile, the army of Saxony, which in September had concluded an alliance with the Swedish king, invaded Bohemia and occupied Prague. In the wake of these developments, the emperor, who in 1630 had dismissed Wallenstein at the request of the princes, placed him again in command of the imperial army in 1632.

On Nov. 16,1632, the Swedish troops, despite the death in battle of their king, defeated the imperial forces at Lützen in Saxony. Nevertheless, the situation of the Swedish army, which had lost its social and political support in Germany, deteriorated seriously. The worsening of Sweden’s military position had grave consequences elsewhere. Earlier, Russia had opened hostilities against Poland, igniting the Smolensk War of 1632–34. Deprived, however, of the assistance promised previously by Gustavus Adolphus, the Russians were defeated at Smolensk and in 1634 signed the Polianovka Peace with Poland. As a result, the Swedish command was forced to transfer some of its troops hastily to the Polish frontier, thereby weakening its army in Germany. On Sept. 6, 1634, in the battle of Nördlingen in southern Germany, the Swedish army suffered a serious defeat at the hands of the combined imperial and Spanish forces. Thereupon the Saxon elector broke his alliance with Sweden and concluded the Peace of Prague with the emperor in 1635. Soon after, the elector of Brandenburg and other Protestant princes followed suit.

Forced by events, Catholic France in 1635 intervened directly against the Hapsburgs on German soil, thereby inaugurating the French period (1635–48) of the Thirty Years’ War. Sweden, after signing the Truce of Stuhmsdorf with the Polish-Lithuanian Commonwealth and the Treaty of Compiégne with France in 1635, was free once again to employ all its forces in Germany. France, in alliance with the United Provinces, was forced into a war with Spain that began in May 1635. In Germany the Swedish and French troops, as well as the imperial and Spanish forces, were engaged mainly in plundering; the population resisted by waging its own bitter partisan war against the marauding invaders. In time, however, the military advantage fell to France and Sweden. With their victories at Breitenfeld on Nov. 2,1642, at Rocroi on May 19, 1643, and at Junkau on Mar. 6, 1645, the two allies raised the prospect that they would end up by dividing Germany between themselves. Yet, as the Hapsburg Catholic camp hovered on the brink of total defeat, the French government, concerned over the success of the English bourgeois revolution of the 17th century and of the French Fronde, moved quickly to terminate the war.

The Thirty Years’ War was formally concluded by the Treaty of Westphalia of 1648. Under the treaty, Sweden received rights to the entry ports of all the navigable rivers of northern Germany; France received lands in Alsace and obtained recognition of its sovereignty over Metz, Toul, and Verdun. Several German principalities, especially Brandenburg, had their territories enlarged. All German princes were empowered de jure to contract treaties with foreign powers, a right they had previously enjoyed de facto. In general, however, the Thirty Years’ War had dire consequences for Germany. Its fragmentation was confirmed in treaties, its population suffered enormous losses, and its economy underwent grave dislocation. Hardest hit were the German peasants.

Meanwhile, the war between France and Spain continued until 1659, when the Treaty of the Pyrenees was signed. With their forces thus pinned down, the two continental powers were unable to organize a campaign by Europe’s feudal monarchies against the English revolution. After the Thirty Years’ War, hegemony in Western Europe passed from the Hapsburgs to France. Yet the Hapsburgs were not completely crushed; they remained a force to be reckoned with in Europe.

From the point of view of military history, the Thirty Years’ War represents a milestone in the development of relatively small and mobile, albeit expensive, mercenary armies. The strength of the belligerents on both sides during most of the war totaled only in the tens of thousands. If the belligerents, therefore, could wage a sustained war, it was because they had the power to raise money to hire troops. The stronger and wealthier states, in brief, could afford to pay smaller states to fight the war for them. In the art of war, the most important innovations—for example, the adoption of linear tactics—occurred in the Swedish army.