The First Silesian War (German: Erster Schlesischer Krieg) was a war between Prussia and Austria that lasted from 1740 to 1742 and resulted in Prussia's seizure of most of the region of Silesia (now in south-western Poland) from Austria. The war was fought mainly in Silesia, Moravia and Bohemia (the lands of the Bohemian Crown) and formed one theatre of the wider War of the Austrian Succession. It was the first of three Silesian Wars fought between Frederick the Great's Prussia and Maria Theresa's Austria in the mid-18th century, all three of which ended in Prussian control of Silesia.
No particular triggering event started the war. Prussia cited its centuries-old dynastic claims on parts of Silesia as a casus belli, but Realpolitik and geostrategic factors also played a role in provoking the conflict. Maria Theresa's contested succession to the Habsburg monarchy provided an opportunity for Prussia to strengthen itself relative to regional rivals such as Saxony and Bavaria.
The war began with a Prussian invasion of Habsburg Silesia in late 1740, and it ended in a Prussian victory with the 1742 Treaty of Berlin, which recognised Prussia's seizure of most of Silesia and parts of Bohemia. Meanwhile, the wider War of the Austrian Succession continued, and conflict over Silesia would draw Austria and Prussia into a renewed Second Silesian War only two years later. The First Silesian War marked the unexpected defeat of the Habsburg monarchy by a lesser German power and initiated the Austria–Prussia rivalry that would shape German politics for more than a century.
Context and causes
In the early 18th century, Prussia's ruling House of Hohenzollern held dynastic claims to various duchies within the Habsburg province of Silesia, a populous and prosperous region contiguous with Prussia's core territory in the Margraviate of Brandenburg. Besides its value as a source of tax revenue, industrial output (particularly minerals) and military recruits, Silesia held great geostrategic importance to the belligerents. The valley of the Upper Oder formed a natural military conduit between Brandenburg, the Kingdom of Bohemia and the Margraviate of Moravia, and whichever power held the territory could threaten its neighbours. Silesia also lay along the north-eastern frontier of the Holy Roman Empire, allowing its controller to limit the influence of the Polish–Lithuanian Commonwealth and of the Russian Empire within Germany.
Brandenburg–Prussia's claims
Prussia's claims in Silesia were based, in part, on a 1537 inheritance treaty between the Silesian Piast Duke Frederick II of Legnica and the Hohenzollern Prince-Elector Joachim II Hector of Brandenburg, whereby the Silesian Duchies of Liegnitz, Wohlau and Brieg were to pass to the Hohenzollerns of Brandenburg should the Piast dynasty in Silesia become extinct. At the time, the Habsburg King Ferdinand I of Bohemia (Silesia's feudal overlord) rejected the agreement and pressed the Hohenzollerns to repudiate it. In 1603, Hohenzollern Elector Joachim III Frederick of Brandenburg separately inherited the Silesian Duchy of Jägerndorf from his cousin, Margrave George Frederick of Brandenburg-Ansbach, and installed his second son, Johann Georg, as duke.
In the 1618 Bohemian Revolt and the ensuing Thirty Years' War, Johann Georg joined the Silesian estates in revolt against the Catholic Holy Roman Emperor Ferdinand II. After the Catholic victory in the 1621 Battle of White Mountain, the Emperor confiscated Johann Georg's duchy and refused to return it to his heirs after his death, but the Hohenzollerns of Brandenburg continued to assert themselves as the legitimate rulers of Jägerndorf. In 1675 the "Great Elector" Frederick William of Brandenburg laid claim to Liegnitz, Wohlau and Brieg when the Silesian Piast line ended with the death of Duke George William of Liegnitz, but the Habsburg Emperor disregarded the Hohenzollern claims and the lands escheated to the Bohemian crown.
In 1685, when Austria was engaged in the Great Turkish War, Emperor Leopold I gave Great Elector Frederick William immediate control of the Silesian exclave of Schwiebus in return for military support against the Turks and the surrender of the outstanding Hohenzollern claims in Silesia. After the accession of the Great Elector's son and successor, Frederick III of Brandenburg, the Emperor took back control of Schwiebus in 1694, claiming the territory had only been personally assigned to the late Great Elector for life. As a young prince, Frederick III had secretly agreed to this repossession in return for Leopold's payment of some of his debts, but as monarch he repudiated the agreement and reasserted the old Hohenzollern claims to Jägerndorf and the Silesian Piast heritage.
Austrian succession
Two generations later, the newly crowned Hohenzollern King Frederick II of Prussia formed designs on Silesia soon after succeeding to the throne in May 1740. Frederick judged that his dynasty's claims were credible, and he had inherited from his father, King Frederick William I, a large and well-trained Prussian army and a healthy royal treasury. Austria was in financial distress, and its army had not been reinforced or reformed after an ignominious performance in the 1737–1739 Austro-Turkish War. The European strategic situation was favourable for an attack on Austria, with Britain and France occupying each other's attentions in the War of Jenkins' Ear and Sweden moving toward war with Russia; the Electors of Bavaria and Saxony also had claims against Austria and seemed likely to join in the attack. Though the Hohenzollerns' dynastic claims provided a legalistic casus belli, considerations of Realpolitik and geostrategy played the leading role in provoking the war.
An opportunity arose for Prussia to press its claims when Habsburg Holy Roman Emperor Charles VI died in October 1740 without a male heir. With the Pragmatic Sanction of 1713, Charles had established his eldest daughter, Maria Theresa, as the successor to his hereditary titles. Upon his death she duly became ruler of Austria, as well as of the Bohemian and Hungarian lands within the Habsburg monarchy. During Emperor Charles's lifetime the Pragmatic Sanction had been generally acknowledged by the imperial states, but when he died it was promptly contested by Prussia, Bavaria and Saxony.
Frederick saw in Austria's female succession an opportune moment for the seizure of Silesia, calling it "the signal for the complete transformation of the old political system" in a 1740 letter to Voltaire. He argued that the Pragmatic Sanction did not apply to Silesia, which was held by the Habsburgs as a part of the imperial demesne rather than as a hereditary possession. Frederick also argued that his father had assented to the Sanction in return for assurances of Austrian support for Hohenzollern claims on the Rhenish Duchies of Jülich and Berg, which had not yet materialised.
Meanwhile, Prince-Elector Charles Albert of Bavaria and Prince-Elector Frederick Augustus II of Saxony had each married one of Maria Theresa's older cousins from a senior branch of the House of Habsburg, and they used these connections to justify claims to Habsburg territory in the absence of a male heir. Frederick Augustus, who ruled Poland-Lithuania in personal union, was especially interested in gaining control of Silesia to connect his two realms into one contiguous territory (which would nearly surround Brandenburg); Frederick's concern to prevent this outcome contributed to his haste in moving against Austria when the contested succession provided an opportunity.
Moves toward war
As Prussia reactivated its Silesian claims and prepared for war against Austria, several other European powers made similar moves. Charles Albert of Bavaria launched a claim to the imperial throne along with the Habsburg territories of Bohemia, Upper Austria and Tyrol, while Frederick Augustus of Saxony laid claim to Moravia and Upper Silesia. The Kingdoms of Spain and Naples hoped to seize Habsburg possessions in northern Italy, while France, which viewed the Habsburgs as traditional rivals, sought control of the Austrian Netherlands. The Electorates of Cologne and the Palatinate joined these to form an alliance known as the League of Nymphenburg, which aimed at the diminution or destruction of the Habsburg monarchy and its dominant position among the German states.
Austria was supported by Great Britain (in personal union with the Electorate of Hanover) and, eventually, Savoy–Sardinia and the Dutch Republic; the Russian Empire under Empress Elizabeth also indirectly took Austria's side in the wider conflict by making war against Sweden (a French ally at the time). Maria Theresa's aims in the conflict were, first, to preserve her hereditary lands and titles and, second, to win or compel support for the election of her husband, Duke Francis Stephen of Lorraine, as Holy Roman Emperor, defending her house's traditional pre-eminence within Germany.
After Emperor Charles's death on 20 October, Frederick quickly resolved to strike first; on 8 November he ordered the mobilisation of the Prussian army, and on 11 December he issued an ultimatum to Maria Theresa demanding the cession of Silesia. In return, he offered to guarantee all other Habsburg possessions against any attack, pay a large cash indemnity, acknowledge the Pragmatic Sanction, and give his vote as elector of Brandenburg in the imperial election to Maria Theresa's husband. Not waiting for a response, he and his troops advanced into Silesia.
Methods and technologies
European warfare in the early modern period was characterised by the widespread adoption of firearms in combination with more traditional bladed weapons. Eighteenth-century European armies were built around units of massed infantry armed with smoothbore flintlock muskets and bayonets. Cavalrymen were equipped with sabres and pistols or carbines; light cavalry were used principally for reconnaissance, screening and tactical communications, while heavy cavalry were used as tactical reserves and deployed for shock attacks. Smoothbore artillery provided fire support and played the leading role in siege warfare. Strategic warfare in this period centred around control of key fortifications positioned so as to command the surrounding regions and roads, with lengthy sieges a common feature of armed conflict. Decisive field battles were relatively rare, though they played a larger part in Frederick's theory of warfare than was typical among his contemporary rivals.
The Silesian Wars, like most European wars of the 18th century, were fought as so-called cabinet wars in which disciplined regular armies were equipped and supplied by the state to conduct warfare on behalf of the sovereign's interests. Occupied enemy territories were regularly taxed and extorted for funds, but large-scale atrocities against civilian populations were rare compared with conflicts in the previous century. Military logistics was the decisive factor in many wars, as armies had grown too large to support themselves on prolonged campaigns by foraging and plunder alone. Military supplies were stored in centralised magazines and distributed by baggage trains that were highly vulnerable to enemy raids. Armies were generally unable to sustain combat operations during winter and normally established winter quarters in the cold season, resuming their campaigns with the return of spring.
Course
Silesian campaign of 1740–41
The Prussian army had massed quietly along the Oder during early December 1740, and on 16 December, without a declaration of war, Frederick moved his troops across the frontier into Silesia. The Prussian force consisted of two corps totalling 27,000 soldiers, while Silesia was defended by an Austrian garrison of only 8,000 men. The Austrians were able to offer only light resistance and garrison a few fortresses; the Prussians swept through the province, taking control of the capital at Breslau without a fight on 2 January 1741. The fortress at Ohlau was also taken without resistance on 9 January, after which the Prussians used it for their winter quarters. By the end of January 1741, almost the entirety of Silesia had come under Prussian control, and the remaining Austrian strongholds of Glogau, Brieg and Neisse were besieged.
After leaving winter quarters in early 1741, the Prussian forces began a spring campaign, and on 9 March Prince Leopold II of Anhalt-Dessau took Glogau by storm. In late March, an Austrian force of around 20,000 under the command of Wilhelm Reinhard von Neipperg crossed the Sudetes mountains from Moravia and broke the siege of Neisse on 5 April, after which the main Prussian force manoeuvred to oppose its advance. The two armies engaged each other near the village of Mollwitz on 10 April, where the Prussians under Marshal Kurt von Schwerin successfully stopped the Austrian advance in the Battle of Mollwitz. Neither army acquitted itself well at Mollwitz, and Frederick at one point fled (on Schwerin's advice) to avoid capture, but the Prussians held the field and subsequently portrayed the battle as a victory. Brieg surrendered to the Prussians on 4 May, after which the main Prussian force encamped through the succeeding months near Neisse, facing off against Neipperg's Austrians but fighting little.