Thirty Years' War: A War for Religious Dominance in Europe

The Habsburg dynasty faced many challenges during its reign. One of the biggest was the Thirty Years' War, which affected nearly all European countries. Beginning as a religious conflict between Protestants and Catholics, this conflict quickly evolved into a political struggle and grew into a war among the most powerful dynasties for hegemony in Europe. The Holy Roman Empire entered the 17th century as a fragmented state, with dozens of small principalities that acknowledged the emperor's authority only on paper. Seven of the most influential rulers had the right to elect the emperor. Nevertheless, since the imperial crown was of little interest to anyone, as it brought only losses, it became firmly associated with the Habsburgs. Political fragmentation was exacerbated by a religious schism. In the north of the empire, Protestants predominated, while the south remained Catholic. The 16th century was marked by several religious wars, which ended with the Peace of Augsburg and the achievement of a compromise that allowed each ruler to establish the faith they deemed appropriate in their territories. Still, neither side was willing to accept this peace and considered it necessary to eliminate their opponent. The Protestants united in the Evangelical Union, while their adversaries formed the Catholic League. Emperor Matthias I was moderate in his religious policy. He was loyal to the Protestants and supported peace in the empire. Even so, his surroundings were much more radical, including his cousin and heir to the throne, Archduke Ferdinand. It is he who was attributed with the quote, I would rather rule a desert than a state full of heretics. Therefore, it is not surprising that these words turned out to be prophetic. Despite being part of the Habsburg Empire, Bohemia had plenty of rights and privileges. Real power belonged to the local parliament, the Diet, where the aristocracy, lords, sat. In the 15th century, a local Protestant movement emerged in Bohemia. The Hussite movement, named after Jan Hus, a theologian who questioned the doctrines of the Catholic Church and introduced his own more accessible version of Christianity for the Czechs. This provoked the Hussite Wars. The Hussites achieved several significant victories, but ultimately lost. Some of the Hussites, known as the Chalice Faction, managed to secure the right to practice their version of Christianity while remaining the main political force in the kingdom. By the 16th century, Lutheranism and Calvinism spread from Germany to Bohemia, making it predominantly a Protestant state. For a time, the Habsburgs, who supported Catholicism, did not oppose this. In fact, Emperor Rudolf II even chose Prague as his capital. The situation changed when the childless Matthias I was nearing death, and Archduke Ferdinand was already preparing to inherit power. In 1617, the Archduke arrived in Prague. During his coronation, he refused to promise not to violate the religious rights of Protestants. The following year, the king's governors began closing Protestant churches. In response, on May 23rd, the Defenestration of Prague occurred. A group of Protestants stormed Prague Castle and threw three royal officials out of the windows. A rebellion swept across Bohemia. The rebels captured Prague, stripped the local Catholics of their possessions, and gathered an army to fight against the Habsburgs. Additionally, the Evangelical Union hired the army of General Ernst von Mansfeld to assist the insurgents. It was Mansfeld's mercenaries who captured the important fortress of Pulzen, thereby blocking the path of the Catholic mercenaries, who were already preparing to invade Bohemia. In the summer of the following year, the Czechs, led by Heinrich Matthias von Thurn, marched to Vienna, but they did not manage to besiege the city. When Count de Bekoy defeated Mansfeld's mercenaries in the Battle of Sablit, Thurn had to return home. The Czech rebels offered the crown to the elector Palatine Frederick V, who agreed to take it. The Czechs were also supported by the Transylvanian prince Gabriel Bethlen, who invaded the Habsburg territories with his own army, and even briefly besieged Vienna. However, the complex political situation in Hungary forced him to return home, although he left his soldiers hired by the Czechs. When Bethlen was standing near Vienna, Ferdinand was preoccupied with his own imperial elections. It was only in 1620 that he turned his attention to the rebelling Czechs. The troops of the Catholic League, led by the talented military leader Johann von Tilly, marched on Prague, where they encountered the Protestants near White Mountain. The Catholics had the advantage in both numbers and the quality of troops. Count Tilly personally led the attack, forcing the Transylvanian mercenaries to flee the battlefield. Following them, the German soldiers also retreated. The Czechs fought to the last. Most preferred death on the battlefield to fleeing. King Frederick fled as soon as he learned of the defeat. Due to his brief reign, his opponents mockingly dubbed him the Winter King. In Bohemia, self-governance was abolished, and the Czech nobility was stripped of their privileges. A process of Catholicization began. After dealing with the Czech uprising, Emperor Ferdinand II turned his attention to Frederick's German territories. In the summer of 1620, the Spanish occupied the Rhenish Palatinate. Only the capital remained free, where a garrison, reinforced by English mercenaries, held out under siege for an entire year. During this time, the Upper Palatinate was occupied by the Bavarians, who would eventually annex it. The Emperor proposed to strip Elector Frederick and his possessions of their titles. Some princes protested, viewing this decision as an infringement on their own rights, and gathered troops to wage war against the Emperor. There was still the army of General Mansfeld. Despite the defeat in Bohemia, it was not destroyed, and the army moved westward. Following them was Count Tilly. In the Battle of Minglesheim, Mansfeld even managed to fend off this pursuit. In May of that same year, Count Tilly defeated the Baden forces in the Battle of Wimpfen. After a few more losses for the Protestants, General Mansfeld, sensing defeat in Germany, enlisted in the war in the Netherlands, where the chances of victory were much higher. Count Tilly defeated Christian of Brunswick twice, forcing him to leave Germany and enlist in military service in the Netherlands. After this, he captured Heidelberg, completely occupying the Palatinate. For a few years, peace prevailed in the Empire, though the flames of war were still ahead. After their defeats, the Protestant princes sought external support for a revanche. In addition to the Protestant allies of England and the Netherlands, they found an unofficial ally in Catholic France. The talented politician Cardinal Richelieu viewed the Habsburgs, who surrounded France on three sides, as Paris' main adversary. Thus, despite his status as a Catholic cardinal, he was willing to finance the Protestants to weaken the Habsburgs. Almost all subsequent military campaigns in this war would be conducted with French money. A more open ally became King Christian IV of Denmark. The Danes, who practiced Protestantism, did not want strong Catholics in neighboring Germany. Additionally, the King of Denmark had territorial claims against the Habsburgs. In 1625, Christian IV entered Lower Saxony and began recruiting mercenaries there. After which, he moved on to Thuringia. General Mansfeld also returned to Germany with his troops to fight against the Catholics. Ferdinand was dissatisfied but could do nothing about it, as Christian IV, in addition to the Danish crown, also held the title of Duke of Holstein and, according to imperial law, had rights to such actions. Moreover, the Protestants of Lower Saxony elected him as the commander of the imperial forces in the local district. This created a comical situation where the Danish king, preparing to fight against the emperor of the Holy Roman Empire, received a military position within that same empire. At that time, the Catholic Czech noble Albrecht von Wallenstein made an interesting proposal to Ferdinand. If the emperor did not have the funds for another army of mercenaries, he could recruit these soldiers by allowing them to pillage and extort tributes. The emperor agreed and Wallenstein quickly gathered 30,000 soldiers and set out against the Danish king, ravaging the lands along the way. In April 1626, Wallenstein's mercenaries intercepted Mansfeld's troops near Dessau. Wallenstein forced the enemy into a disadvantageous position, compelling them to storm a bridge over the Elbe. In these battles, the Protestants suffered heavy losses and Mansfeld was forced to retreat. On the way, he lost half of his army due to desertion and minor skirmishes. With the remnants of his force, Mansfeld headed towards Hungary. He intended to fight the Habsburgs from the south, but it is unclear what his specific plans were moving forward. Ultimately, the Protestant general died at the end of 1626 in Sarajevo. In the summer of that year, Count Tilly secured victory for the Catholics in the Battle of Lutter. The Danes lost a third of their army and all their artillery. The Danish king lost control over Lower Saxony and returned to his homeland. By the end of 1627, Catholic forces had completely occupied Jutland. Wallenstein captured Mecklenburg, where he laid siege to Straslund. The commander needed ships for landing on the Danish islands, where he planned to finish off Christian IV. The Danish king preempted these plans by landing in Mecklenburg himself, but suffered defeat again and requested peace. The treaty was signed in Lübeck. Christian IV renounced his claims. Wallenstein received the duchies of Friedland and Mecklenburg, stepping away from military affairs. Emperor Ferdinand II issued a decree for the return of the former possessions and privileges to the Catholic Church, and he was already preparing to celebrate his triumph. At that time, the rest of Europe viewed Sweden as a poor and backward kingdom, whose army posed no threat to the victorious Catholic forces. But the Swedes made a true revolution in military affairs. Instead of relying on mercenaries, Sweden formed its army from the general population, recruiting soldiers for long-term service. This system allowed the Swedes to maintain a combat-ready army of 45,000 soldiers. Swedish king Gustav II Adolf had gained fame as a talented military commander from a young age. In light of the Danish king's defeats, France sought to form an alliance with the Swedes, hoping they would lead the war against the Habsburgs. Paris promised the Swedish king to finance mercenaries and mediate with the Protestant princes of Germany. Gustav II Adolf, a fervent Protestant, was eager to fight against the Catholic Habsburgs, even if he was being funded by the Catholic Bourbons. In the summer of 1630, King Gustav landed in Pomerania, Usedom Island, with an army. By recruiting German mercenaries, he increased his forces to 40,000 soldiers and besieged Frankfurt-an-der-Oder to secure a foothold for advancing into Germany. During this time, German Protestants began to join the Swedish side, with the city of Magdeburg being one of the first to do so. Count Tilly did not want to lose such an important city as it would open the way for the Swedes into the heart of Germany. Therefore, the Catholic forces besieged Magdeburg. Although Frankfurt fell sooner, the Swedes were unable to assist Magdeburg in time. And in May 1631, Imperial troops captured and plundered the city. Almost all its inhabitants were killed. The event, known as the Magdeburg's Wedding, became the bloodiest chapter of the Thirty Years' War. Count Tilly did not want to allow the Elector of Saxony, Johann Georg I, to join the Swedes, so he personally led his troops into Saxony. Nonetheless, the fate of Magdeburg only reinforced Johann Georg I's desire to ally with the Swedes. This provided the Tilly's army the opportunity to plunder Leipzig. Still, the Catholic forces could not enjoy their spoils for long. Just three days later, the Swedish army approached and defeated the Catholics at the Battle of Breitenfeld. Saxony was cleared of the Catholic army, and the Protestants achieved their first major victory in the war. The victory of the Catholics in the small Battle of Bamberg could not halt the advance of the Swedes. Just a month later, King Gustavus inflicted a defeat on Count Tilly along the banks of the Rhine. Here, the Finnish cavalry distinguished themselves, spearheading the successful assault of the Swedish army. The Catholic army was virtually annihilated, and Tilly suffered a mortal wound. As a result, the Swedes opened the path to Vienna. In such a catastrophic situation, Emperor Ferdinand once again turned to Wallenstein. Utilizing the same recruitment method, he quickly amassed 50,000 soldiers and set out for Bavaria. With skilled tactics, he blocked Gustavus II's path with a small army in Nuremberg. The Swedish king was only saved by the arrival of his main force. Still, even with his reinforcement, he was unable to defeat Wallenstein at the Battle of Fürth, forcing the Swedes to retreat northward. Wallenstein set out to pursue them. In November, after lengthy maneuvers, the armies met in Saxony at Lützen. Gustavus II Adolf was waiting for the arrival of Protestant allies. But when he learned that Wallenstein was nearby, he decided to attack him, hoping to use the element of surprise to defeat the Catholics. He succeeded in his endeavor. Wallenstein's army suffered significant losses and left the battlefield. All the same, the victory came at a high cost for the Swedes, including the loss of their king. After the death of the popular king, the enthusiasm of the Swedes for the war significantly waned. German mercenaries began to rise to prominence in the Swedish army. One of them, Bernard of Saxe-Weimar, took on the actual command of the Protestant forces. He was a young commander, not yet 30 years old, though he had gone through military training in the armies of General Ernst von Mansfeld and Kings Christian IV and Gustav II. Bernard renewed the offensive towards the Danube, and in November 1633, after three attempts, he captured Regensburg. The nobility in Vienna did not like Albrecht von Wallenstein. To them, he was a provincial upstart who had simply gotten lucky. The emperor was often told that Wallenstein was planning to betray him, either by switching sides to the Protestants or by seizing power in the empire himself. After the defeat at Lützen, the commander's authority began to decline. When the emperor learned of his secret negotiations with the Protestants, he ordered his execution. Wallenstein was killed by his own guards on the way to Vienna. Wallenstein's army was transformed into an imperial one and reinforced with hired Spanish tercios, the most capable troops in the Catholic League. The new army was led by Prince Ferdinand. He had trained in military affairs under Wallenstein's supervision and would often use his methods of warfare. By July 1634, Ferdinand had taken Regensburg, after which he defeated the Swedish forces in the Battle of Nordlingen. The defeat was a true disaster for the Protestants. The Swedes began their retreat to Pomerania. The Saxon elector, who had already been reluctant to fight for the Swedes, switched sides to the Habsburgs. He even attempted to hold back the Swedes, but, after suffering defeat at Demetz, ultimately allowed them to pass northward. The situation was even worse for the German princes. Abandoned by the Swedes, they were unwilling to fight the Habsburgs on their own. Some, like Bernard of Saxe-Weimar, sought a way to France. Nevertheless, most Protestants opted for reconciliation with the emperor. In 1635, a peace treaty was signed in Prague that restored the Holy Roman Empire to the same status it had before the Thirty Years' War. Yet, this treaty did not bring an end to the war. For a long time in this war, France only financed the opponents of the Habsburg dynasty to weaken them. Internal conflicts and the struggle for influence in Italy prevented the French from fully intervening in the conflict. But, when the German Protestants sought peace with the emperor, Paris decided to intervene in the war. The Habsburg army had already been weakened due to the prolonged conflict, and the French hoped to defeat them easily. Immediately after declaring war on the Habsburgs, the French defeated their army at Les Auvins, temporarily occupying the Spanish Netherlands. A second French army invaded Italy. But, within a year, the Spanish-German forces, led by Fernando of Austria, reclaimed their territories and themselves invaded France, At that time, General Matthias Gallus invaded Burgundy. France found itself on the brink of defeat. The French were saved by the Swedes, with whom they had recently formed an alliance. In 1636, the Swedish army, led by General Johan Bena, launched a campaign. The Swedes defeated the Saxons in the Battle of Wittstock and occupied Saxony, Thuringia, and Hesse. The Habsburgs had to recall General Gallus back to Germany, where he faced significant difficulties in reclaiming territories from the Swedes. This was enough for the French to retake Corbie and drive the enemy from their lands. Once again, Bernard von Saxe-Weimar made his mark. With his army, reinforced by the French, he captured Alsace. The war once again shifted to the Holy Roman Empire. The French attempted to shift the fighting to Spain as well. In the summer of 1638, they destroyed the Spanish fleet near Getaria. However, on land, they suffered defeat and had to retreat. Far more important for the war were the events along the Rhine. Here, General Saxe-Weimar crossed the Rhine and defeated the imperial forces in the Battle of Rheinfelden. After laying siege to Brissach for six months, he captured the city and opened the way for the French into Germany. Yet, the prince died under unclear circumstances and his troops pledged allegiance to France. The first to cross the Rhine was the French army of Duke de Longville, where real command was in the hands of the young Count de Gabriant, who would be awarded the title of Marshal for this campaign. After occupying the Palatinate, he marched to meet the Swedes. During this time, the Swedish army managed to defeat General Gallus. Capture and plunder Bohemia and, together with the French, conducted a raid on Regensburg, during which they lost their commander, who died of cirrhosis. In the summer of 1641, the Franco-Swedish army defeated the Bavarians and then split up. The following year, Count de Gabriant crushed the Habsburg forces at the Battle of Kempen, while Lennart Torstensson defeated the Catholic troops in the Second Battle of Breitenfeld. The French also anticipated significant successes on other fronts. In Italy, as early as 1640, Viscount de Touraine captured Turin. On the Iberian Peninsula, the Portuguese, taking advantage of Madrid's weakening, rose up and diverted Spanish attention. By 1641, French troops had completely conquered the county of Artois. A year later, in the north, they captured the principality of Sedan, and in the south, Roussillon. The conquest of the latter was intended to culminate in the capture of Barcelona, where the French received assistance from Catalan separatists. Yet, this war dragged on until 1659, and France was unable to secure Barcelona. In 1643, the Spanish invaded France for the second time from the north. French forces, led by Duke Louis II of Comte de Bourbon, marched out to meet them. Despite his young age, he proved to be a talented commander. In the Battle of Roc Roy, the French first employed linear infantry tactics, which Europeans would adopt until the late 19th century. The Spaniards suffered a crushing defeat in this battle, being sidelined from active combat for a long time. Duke Comte de Bourbon returned triumphantly to Paris. The last hope for the Habsburgs rested on the Bavarian troops, led by the talented commander, the Lorraine-born Franz von Mercy. In 1643, he defeated a 15,000-strong French army, composed of former mercenaries of Bernard Saxe-Weimar in the Battle of Tuttlingen, and subsequently captured Freiburg. As a result, Louis II of Comte de Bourbon headed to Germany to take command personally. In the summer of 1644, the French clashed with imperial troops outside the walls of Freiburg. At the cost of double the losses compared to their opponent, the French emerged victorious. Though in retreating, von Mercy lured Marshal de Turenne into an ambush and defeated him in the Battle of Mergentheim. While the Bavarians were occupied with the French in the west, Swedish General Torstensson invaded Bohemia. He laid siege to Prague, and in the spring of 1645, defeated imperial troops in the Battle of Jankow. The Swedes occupied Bohemia for the second time. Meanwhile, the French began their advance, rapidly capturing German territories. Von Mercy attempted to stop them. In the Second Battle of Nördlingen, he inflicted significant losses on the French, but was killed in the battle. After the death of their commander, the Bavarian troops capitulated. Louis II de Condé-Bourbon returned to France. For him, as a Frenchman, the war for the expansion of France was more important than the political interests in Germany. In 1646, he laid siege to Dunkirk. To completely block Dunkirk, the French had to rent Dutch ships. After heavy fighting, the French forced the Spanish to surrender the fortress. This time, Dunkirk remained in French hands for only six years. At this time in Germany, Franco-Swedish forces led by Marshal de Touraine and General Rangel were preparing for a campaign against Austria. Realizing the hopelessness of the situation, the Bavarian elector requested peace. Even so, just a year later, after gathering his troops, he violated that peace and attempted to capture Magdeburg. The campaign was unsuccessful, and soon the French and Swedes launched a counter-offensive, defeating the imperial forces. The French occupied Bavaria, while the Swedes occupied Bohemia. The Allies had a clear path to Vienna. In response, Emperor Ferdinand III requested peace. At the same time, the Emperor's younger brother, Leopold Wilhelm of Habsburg, attempted a third invasion of France from the north. All the same, his forces were defeated by Prince Condé at the Battle of Lens. Meanwhile, the commander of the Catholic army, Piccolomini, regained Bavaria. Negotiations began as early as 1644, but each side prolonged them in hopes of gaining more. Since this war was extensive, several peace treaties were signed to conclude it in the cities of Westphalia. Because of this, the peace is known as the Peace of Westphalia. It confirmed the principle of equality between Protestants and Catholics in the Holy Roman Empire. German princes were allowed to conduct their politics at their discretion. Some principalities, such as Saxony and Brandenburg, expanded their territories. Sweden gained Bremen and western Pomerania, while France, which continued to fight Spain, acquired lands in Lorraine and Alsace. The Habsburgs were forced to recognize the independence of Switzerland and the Netherlands. The war, which began as a religious conflict and ended as a struggle for hegemony in Europe, became a catastrophe for Germany. Most of its lands were devastated by war. The population fell by a third, and in some areas, by as much as half. The Westphalian peace cemented fragmentation, preventing the Germans from establishing a unified state for another 200 years.