The War of the Austrian Succession (1740 to 1748) was a major conflict fought between the great powers of Europe, sparked by a dispute over the right of a woman – Maria Theresa – to succeed to the Austrian throne. Maria Theresa was supported by the Habsburg monarchy, Great Britain, the Dutch Republic, Hanover, Saxony, and Russia, a coalition known as the Pragmatic Alliance.

She was opposed by an anti-Habsburg coalition that included France, Prussia, Bavaria, and Spain. Though the war was primarily fought in Europe, it also played out in colonies across the world; correlating conflicts included the War of Jenkins' Ear and King George's War in the Americas, and the First Carnatic War in India. Hostilities ended with the Treaty of Aix-la-Chapelle in 1748, which largely failed to address the underlying causes of the war.

On 20 October 1740, the Holy Roman Emperor Charles VI died after a brief illness, setting off a crisis that would reverberate across Europe. Having been unable to produce a male heir, the emperor had spent much of his reign laying the groundwork for his eldest daughter, Maria Theresa, to succeed him. Back in 1713, he had issued an edict known as the Pragmatic Sanction, which allowed for female inheritance should the Habsburg dynasty go extinct in the male line. But this edict contradicted the prevailing Salic Law, which stipulated that only males could inherit, upsetting many of the princes in the Imperial Diet.

Therefore, when Charles VI died, Maria Theresa ascended the Habsburg throne on precarious ground. It did not help that her tutors had neglected to educate her in statecraft, focusing instead on traditional feminine virtues, like reading, dancing, and music. Maria Theresa must have felt quite unprepared for the crisis that faced her, as her rivals began to circle like vultures.

The most apparent threat was Charles Albert, Elector of Bavaria. Though not a Habsburg himself, Charles Albert could lay claim to the imperial throne by virtue of his descent from the House of Wittelsbach, one of the oldest German families "from which in part the creation of the empire issued forth" (quoted in Browning, 38). At the same time, the royal court of Spain celebrated Charles VI's death, its hungry eyes turning to the underdefended Habsburg territories on the Italian peninsula.

But by far Maria Theresa's most dangerous adversary would prove to be the fledgling Kingdom of Prussia, where the youthful King Frederick II (later Frederick the Great) had just succeeded his father. Much like Frederick himself, Prussia was a young state, hungry for glory and itching to prove itself on the world stage. To increase Prussia's standing in the German world, Frederick looked to Silesia, one of the wealthiest and most developed provinces in the Habsburg Empire. Taking advantage of the chaos that accompanied Maria Theresa's ascension, Frederick gathered his army and invaded Silesia on 16 December 1740. Whether he realized it or not, the Prussian king had just set a fire that would blaze across Europe and, indeed, the world.

Though the Austrians had been preparing for war in Italy and Hungary, they were taken by surprise by Frederick's blitzkrieg into Silesia. In less than two weeks, Frederick had overrun the entire province, with only a handful of forts still in Austrian hands. The Austrians responded swiftly – in early 1741, Count Wilhelm Reinhard von Neipperg led a counteroffensive into Silesia. Though he had not been expecting the Austrians to strike so soon, Frederick marched his men through the snow and met Neipperg's army at the Battle of Mollwitz (10 April).

At first, the outcome was in doubt, as the fortunes of battle swayed back and forth; indeed, Frederick even had to flee the battlefield to avoid capture. But the day was eventually won by the Prussian infantry, who advanced with such rigorous discipline that they appeared to be a moving wall. The military tactician Carl von Clausewitz would later write that the Prussian troops "achieved a level of perfection in the use of firepower that has still not been surpassed" (quoted in Blanning, 103). In the end, the Austrians retreated, each side leaving roughly 5,000 men dead or wounded on the frost-covered field.

The other European powers had been watching Frederick's campaign with interest, with Mollwitz convincing them that Austria was weak. France was particularly eager to weaken Habsburg power in Central Europe and began to champion Charles Albert's claim to the imperial throne. Alarmed, Maria Theresa quickly negotiated a truce with Frederick, in which she ceded Lower Silesia to Prussia. But the damage had already been done. That autumn, a combined Franco-Bavarian army invaded Bohemia and, on 26 November, captured Prague. There, Charles Albert was crowned King of Bohemia, a title that was traditionally held by the emperor.

A few months later, he gained the support necessary to be elected Charles VII, Holy Roman Emperor, the first non-Habsburg to hold the title in over three centuries. It was clear to almost everyone, however, that Charles VII was little more than a French puppet. Once again, the Austrians were quick to retaliate. In a rapid winter offensive, they retook much of the territory that had been lost in Upper Austria before invading Bavaria. The Franco-Bavarian army, plagued by internal discord and leadership disputes, was slow to respond.

But just when it seemed the tables might have turned, things began to go wrong for the Austrians. In February 1742, 25,000 Spanish soldiers landed in Italy. That same month, Frederick II was enticed to rejoin the war and invaded the Habsburg province of Moravia with 30,000 men. Maria Theresa sent her brother-in-law, Prince Charles of Lorraine, after the untrustworthy Prussian king, with the two armies clashing at the Battle of Chotusitz (17 May 1742). Though the battle itself was inconclusive, the Austrians withdrew first, leaving the Prussians in control of the field. This setback once again forced Maria Theresa to negotiate with Frederick. In June 1742, her ministers signed the Treaty of Breslau, which gave Prussia control over all Silesia in exchange for its withdrawal from the war.

The treaty freed up thousands of Austrian troops to retake Prague, as the occupying French and Bavarian forces had been whittled down by attrition. The Austrians laid siege in June, and conditions in Prague only worsened. Unsure of the loyalties of the civilians, the French imposed strict curfews, shooting anyone who was out at night. But eventually, the occupiers ran out of food. In December 1742, 14,000 French and Bavarian soldiers escaped from Prague and snuck past the Austrian line, leaving behind their sick and wounded. Prague was once again under Habsburg control.

Although Austria had been fighting on its own thus far, it was not entirely friendless. King George II of Great Britain was eager to both stymy the ambitions of France and humble his nephew Frederick II, whom he referred to as "a faithless prince" who "must have his wings clipped" (quoted in Browning, 49). Hanover, too, was eager to punish the aggression of its fellow German states, Prussia and Bavaria, while the Dutch Republic was treaty-bound to come to Austria's aid. These nations pooled their military resources into a single force called the Pragmatic Army – this name signaled the allies' intentions to uphold the Pragmatic Sanction and Maria Theresa's right to rule.

In April 1743, the 60,000-man Pragmatic Army landed along the Rhine. Initially, spirits were high; one eyewitness recorded the camaraderie between the British and Hanoverian soldiers, who drank, talked, and sang together "a vast deal, without understanding one syllable of what they say to one another" (quoted in Browning, 135). However, George II insisted on leading the army himself and ordered it not to move until his arrival. As such, the army languished in one spot for months, running through its supplies. Bands of soldiers began roving the countryside, plundering food from unfortunate civilians.

George II arrived on 19 June, only to find that the army was in no condition to launch an offensive. He and his generals decided to retreat to the safety of the Netherlands to regroup. But no sooner had they begun their retreat than they found themselves blocked by a French army under the Duke of Noailles. Eager to destroy the Pragmatic Army in its tracks, Noailles attacked on 27 June at the Battle of Dettingen. The elite Maison du Roi cavalry charged the allied line three times but was bloodily repulsed in each instance. This was followed by a disjointed French infantry charge, which was likewise beaten back. After three hours of fighting, the French withdrew, leaving 5,000 casualties, compared to around 2,000 allied losses.

Although their morale was buoyed by this unexpected victory, the Pragmatic Army continued its retreat, forced to abandon their wounded in their wake (Dettingen holds the distinction of being the last time a British monarch commanded an army in battle). The other important battle of 1743 occurred in Italy, where Spanish and Austrian forces clashed at the Battle of Campo Santo (8 February). Though not as big as other battles, Campo Santo was, per capita, the bloodiest battle of the war, as one quarter of all combatants fell as casualties. The Spanish were defeated, and for the moment, Maria Theresa's holdings in Italy were secured.

The following year, the conflict continued to escalate. In February 1744, the British Royal Navy fought an inconclusive battle with a Franco-Spanish fleet in the Mediterranean, just off Toulon; the opposing fleets traded intense broadsides that reduced several ships to splinters and left hundreds of men dead or wounded. The next month, France officially declared war on Britain and began amassing troops in Dunkirk for an invasion of the British Isles. Britain was saved from invasion not by its fleet but by a storm that whipped up in the English Channel and damaged many of the French ships. This was not the only misfortune to befall French military plans that year. In August, King Louis XV of France fell dangerously ill with smallpox. Though he eventually recovered, his illness threw the kingdom into chaos and caused the French war effort to grind to a halt.

Likewise, Prussia, too, met with setbacks. The same month that Louis XV was confined to his sickbed, Frederick II was induced to rejoin the war for the third time. He invaded Bohemia with 80,000 men and, by mid-September, had captured Prague. However, for the first time, the Prussian king overplayed his hand. Fearful of Frederick's ambitions, Saxony allied with Austria and declared war on Prussia. In October, a 75,000-man Austro-Saxon army marched into Bohemia, hot on Frederick's heels. By now, the Prussian army was being ravaged by dysentery and starvation, leaving Frederick with no choice but to retreat into Silesia. By the time he reached friendly territory in December, he had lost 36,000 men to attrition.

The anti-Habsburg alliance suffered a major blow on 20 January 1745 when their puppet emperor, Charles VII, died of gout. His son and heir, Maximilian III Joseph, succeeded him as Elector of Bavaria but found that most of his country was still under Austrian occupation. The Bavarians made one last, desperate attempt to drive the Austrians out but were defeated at the Battle of Pfaffenhofen (15 April). A week later, Maximilian Joseph signed the Treaty of Füssen, in which he made peace with Austria, renounced his claims to the imperial throne, and agreed to support Maria Theresa's husband, Francis Stephen of Lorraine, as the next Holy Roman Emperor. Indeed, her husband received the necessary support to be elected and was crowned Francis I, Holy Roman Emperor, later that year. With the exit of Bavaria, France no longer had much of a reason to keep its armies in Germany and could focus on its main priority – the defeat of Britain.

Maurice de Saxe, the brilliant general who had recently been made a marshal of France, decided to lure the British into a battle by invading the Austrian Netherlands (modern Belgium) and threatening Tournai, a central trade hub for northern Europe. In late April, Saxe laid siege to Tournai. As anticipated, the Pragmatic Army – now under the command of George II's 24-year-old son, Prince William, Duke of Cumberland – began to stir. Saxe wrote to Louis XV, inviting him to watch the battle and share in the glory.

He chose a naturally strong defensive position around the towns of Antoing, Vezon, and Fontenoy, and waited. At dawn on 11 May, the multinational Pragmatic Army, also around 50,000 strong, attacked. After an initial artillery bombardment, Cumberland sent his Dutch troops to assault the French position at Fontenoy. The French, sheltering behind walls and piles of bricks, allowed the Dutch to come within close range before unleashing devastating volleys of musket fire. The Dutch retreated, rallied, and charged again – only to be met with an equally deadly hail of bullets. Next came the British and Hanoverian infantry, advancing in two lines and withholding their fire until they came within 30 paces of the French line. For several excruciating minutes, the British and French traded fire until finally, the French line broke.

Though severely ill and racked with pain, Saxe directed the French troops from horseback, rallying them as he sent wave after wave of cavalry charges to slow down the allied advance. Eventually, the allied attack lost its momentum, and Cumberland ordered a retreat. The Battle of Fontenoy had been the bloodiest battle fought in Western Europe in almost 40 years; the French had lost around 8,000 men, the allies around 12,000. After the battle, Louis XV approached Saxe to congratulate him on his victory. Gesturing to the corpses carpeting the field, the marshal responded, "Sire, now you see what war really means" (quoted in Browning, 212).

As the smoke settled over Fontenoy, another army was preparing to fight for its life in Central Europe. Frederick II had spent the entire year reorganizing his depleted army and, by May, he had gathered some 59,000 men at Glatz (Kłodzko) in Lower Silesia. This came not a moment too soon – on 30 May, Prince Charles of Lorraine led an equally sized Austro-Saxon army into Silesia. Frederick learned where Prince Charles had set up camp and decided to strike rather than wait to be attacked. At dawn on 4 June, the Prussians launched a surprise attack against the Saxon camp. This led to brutal hand-to-hand combat, as the Prussians fought with "demonic bloodlust" (quoted in Browning, 216). By 7 a.m., the Saxons were routed, leaving the Austrian infantry to face the enemy alone. Before long, the Austrians, too, were fleeing, and the Battle of Hohenfriedberg was over.

Frederick had lost around 4,700 casualties, compared to nearly 13,000 Austro-Saxon losses. It was the most brilliant victory of Frederick's career thus far. If there was any doubt that Prussia had the upper hand, it was put to rest when the Prussians again defeated Prince Charles's Austrian army at the Battle of Soor (30 September). On 25 December 1745, a peace agreement was once again reached in the Treaty of Dresden. Maria Theresa agreed to renounce her claims to Silesia, and Saxony promised to pay Prussia a war indemnity of one million crowns. In return, Frederick recognized Maria Theresa's right to rule. Prussia left the war for good this time. Upon his return to Berlin, the triumphant king was cheered by his people and, for the first time, was hailed as ‘Frederick the Great'.

The Treaty of Dresden brought peace to the ravaged lands of Germany, while the ascension of Francis I to the imperial throne all but assured his wife's right to rule in the Habsburg domain. All that was left was for the conflict to resolve itself in the other theaters of war. In the Low Countries, the triumphant French continued their advance through the Austrian Netherlands. Saxe captured Antwerp in February 1746 and, eight months later, defeated another Pragmatic army at the Battle of Rocoux (11 October). By 1747, the French had reached the borders of the Dutch Republic and had begun assaulting the frontier fortifications.

On the Italian front, the anti-Habsburg alliance met with less success. Though the Spanish had defeated the Austrians at the Battle of Bassignano (27 September 1745), they had been unable to effectively exploit the victory. Fighting continued to rage over the next two years, but by the end of 1747, Austria still controlled most of its holdings in northern Italy.

By 1748, most of the belligerent powers were tired. Eight years of perpetual war had certainly taken their toll. The expenses of maintaining armies and waging campaigns had caused most of the nations to fall into debt, while the fear and uncertainty amongst their war-weary populations was leading to political unrest. Peace talks were begun by the ministers of Britain and France, largely at the exclusion of the other powers. Maria Theresa vented her frustration that she was not allowed a seat at the negotiating table, despite the centrality of Austria to the conflict. In the end, Britain and France agreed that the map in Europe would return to the status quo antebellum – i.e., all territories captured during the war would be returned to their original owners.

There were two notable exceptions. First, Austria had to cede the Italian duchies of Parma, Piacenza, and Guastalla to a member of the Spanish Bourbon Dynasty. Second, Prussia got to keep Silesia; this latter concession implicitly recognized the growing importance of Prussia on the European stage. Finally, all signatories were obliged to accept the Pragmatic Sanction of 1713 and, by extension, Maria Theresa's right to rule in Austria. These terms were signed in the Treaty of Aix-la-Chapelle in October 1748, finally bringing the war to an end. The peace treaty was a compromise, however, and nobody left the negotiating table happy. Unresolved tensions would continue to simmer for the next several years, eventually boiling over into the next great European conflict: the Seven Years' War.