The course of the Seven Years’ War
1756
Crossing the Saxon frontier with 70,000 Prussians on August 29, 1756, Frederick entered Dresden, the Saxon capital, on September 10. The Saxon army, numbering no more than 20,000, fell back to Pirna, in the southeast. Prussia offered assurances of its good intentions to Saxon elector Frederick Augustus and his minister, Heinrich, Reichsgraf (imperial count) von Brühl, but those promises, quite naturally, were greeted with mistrust, and an Austrian force of 32,000 under Maximilian Ulysses, Reichsgraf Browne, moved from Bohemia to reinforce the Saxons. To prevent that union, Frederick advanced southward into Bohemia, where he soundly defeated Browne at Lobositz (now Lovosice, Czech Republic) on October 1. Returning to Saxony, Frederick received the capitulation of the Saxons at Pirna (October 16), whereupon he took nearly all of them into his own service. Frederick Augustus and Brühl retired to the former’s kingdom of Poland.
Russia might have dispatched forces to assist Austria at once, but the most-direct route to the conflict lay across Poland, a country that was within the French sphere of influence and largely opposed to Russian designs. For the perfect achievement of an anti-Prussian coalition, it was most desirable, as Kaunitz saw, for Russia and France to come to terms. The Russians, however, saw the new development as an occasion for extracting concessions from France with regard not only to Poland but also to Sweden and Turkey. The French foreign ministry was ready to admit swift passage of Russian troops across Polish territory and thus relieve France of the obligation to help Austria. However, that came into conflict with le Secret du roi, a primary purpose of which was to exclude the Russians from Poland at any cost. In Great Britain the accession of William Pitt the Elder to office as virtual prime minister in November 1756 would have a decisive effect on the development of the war.
1757
After weeks of negotiation at cross-purposes, Mackenzie, having returned to St. Petersburg as France’s official agent, obtained Russia’s accession to the First Treaty of Versailles by secretly pledging that France would assist Russia in the event of an attack by Turkey (December 31, 1756 [January 11, 1757, New Style]). That contradiction of the long-standing Franco-Turkish entente was immediately disavowed by the French government. A personal letter from Louis XV to Elizabeth, the first of an important series, finally secured Russia’s accession to the treaty without the objectionable appendix (April 19). An Austro-Russian offensive alliance against Prussia was concluded on February 2, 1757, with each party undertaking to put 80,000 men into the field and forswearing any separate peace, while secret articles provided for a partition of Prussia.
On May 1, 1757, Austria and France signed the Second Treaty of Versailles, an offensive alliance against Prussia that additionally provided for significant territorial adjustments. Austria was to recover Silesia but would cede the Netherlands to Louis XV and his Spanish Bourbon cousin, Philip, duke of Parma, Piacenza, and Guastalla. Philip’s Italian possessions would then revert to Austria. Militarily, France was to maintain 105,000 men in Germany, in addition to the contingent to be supplied to Austria (which was raised from 24,000 to 30,000), and would grant an annual subsidy of 12 million livres to Austria. Shortly after the treaty was concluded, Bernis was named French foreign minister.
By a large majority of votes in the Council of Princes of the Reich, Austria secured the declaration of a “war of the Empire” against Prussia. Though Hesse-Kassel, Brunswick, and, naturally, Hanover opposed it, some Protestant states supported Austria, despite Frederick’s attempt to pose as the champion of Protestantism against an Austro-French Roman Catholic coalition. In April 1757 the Prussians again advanced into Bohemia. On May 6 the 66,000 Austrians under Browne and Charles, prince of Lorraine and Bar, were routed by Frederick’s force of 64,000 at the Battle of Prague. An Austrian force under Leopold Joseph, Graf von Daun, arrived too late to affect the outcome of the battle, and the Austrians lost more than 14,000 men. Some 16,000 escaped to join Daun while the rest took refuge in Prague itself, which the Prussians, who had taken comparable losses, proceeded to besiege. A month later Daun, with more than 50,000 men, moved to relieve Prague, and Frederick met him with a force of 34,000. On June 18 the two groups met at the Battle of Kolín, and Daun won a great victory, inflicting 13,000 Prussian casualties while suffering just 8,000 of his own. Raising the siege of Prague, the Prussians evacuated Bohemia.
Prussia, meanwhile, was exposed to attack from several directions. The French began their spring campaign by sending Louis-Charles-César le Tellier, comte d’Estrées, with 100,000 men against the so-called Army of Observation, a force of Hanoverians and their allies under the command of William Augustus, duke of Cumberland, a younger son of George II. Defeated at Hastenbeck on July 26, 1757, Cumberland withdrew to Stade, near the Elbe estuary, abandoning the defense of the electorate and Brunswick. French command then passed to Louis-François-Armand du Plessis, duc de Richelieu, and on September 8 he forced Cumberland to sign the Convention of Klosterzeven, which stipulated the disbanding of the Army of Observation and the evacuation of Hanover. Richelieu then advanced on Prussia’s western frontier while another French army, of 24,000, under Charles de Rohan, prince de Soubise, was crossing Franconia to join Austria’s German allies under Joseph Frederick William of Saxe-Hildburghausen. Furthermore, Sweden, having signed an alliance with France and Austria on March 21, invaded Prussian Pomerania in September with the intention of annexing it.
A Russian army of 90,000 men, which had begun to cross Polish territory in May, at last entered East Prussia in August 1757. On August 30 Russian commander Stepan Apraksin inflicted a crushing defeat on the Prussians under Hans von Lehwaldt at Gross-Jägerndorf, west of Gumbinnen (now Gusev, Russia). In a puzzling move, Apraksin then began a retreat, pleading difficulties of supply. It seems that his conduct was caused, partly at least, by a consideration that was long to bedevil Russian affairs—the fact that the empress Elizabeth, who hated Prussia, was in notoriously uncertain health, while her heir, the future emperor Peter III, adored Frederick and opposed the anti-Prussian war. Any Russian general or statesman who did too much harm to Prussia was therefore risking the displeasure of his future master.
Frederick, with Saxony as his main base, decided first to confront the danger from the west, leaving Frederick Francis of Brunswick-Bevern to face the Austrians in Silesia. To prevent Richelieu from joining forces with Soubise and Saxe-Hildburghausen, Frederick marched first toward Halberstadt, but Austrian successes in Silesia, where Brunswick-Bevern was defeated at Moys (near Görlitz) on September 7, made him turn eastward again. Meanwhile, Frederick’s nephew Charles William Ferdinand of Brunswick remained to observe Saxe-Hildburghausen, and a daring Austrian raid on Berlin caused further diversion of Frederick’s forces. Finally, hearing that Soubise and Saxe-Hildburghausen were in Thuringia, Frederick moved to engage them. The Battle of Rossbach followed on November 5, 1757. The combined strength of the French and the Army of the Reich was at least 41,000 against just 21,000 Prussians, but the aggressive Saxe-Hildburghausen and the more-cautious Soubise were at odds. When at last the battle was joined, the greatly superior mobility of the Prussians, with the brilliant cavalry leadership of Friedrich Wilhelm, Freiherr (baron) von Seydlitz won the day. In less than two hours’ fighting, the Prussians inflicted 7,000 casualties on the allies while losing only 550 men. Encouraged by the news of Rossbach, the British government repudiated Cumberland’s Convention of Klosterzeven. The British decided to reinforce the Hanoverians and to transfer the command in western Germany to Frederick’s brother-in-law, Field Marshal Ferdinand of Brunswick. In September a British naval expedition against the French base of Rochefort had been a failure.
In Silesia the Austrians took Schweidnitz (now Świdnica, Poland) on November 11 and Breslau (now Wrocław, Poland) on November 22. Frederick then force-marched his army from Thuringia to support Brunswick-Bevern, and at the Battle of Leuthen (December 5, 1757), he won the greatest of his victories. With 43,000 men, he attacked the 72,000 under Charles of Lorraine and utterly routed them with an unexpected cavalry charge followed by an artillery bombardment. Frederick suffered 6,000 casualties, but Charles lost 22,000 men, including 12,000 who were taken prisoner. Shortly thereafter the Prussians reclaimed Breslau. In the course of the winter, Lehwaldt drove the Swedes back into their own part of Pomerania, where they were able to hold the Prussians outside Stralsund. Frederick’s masterful handling of well-disciplined troops, combined with Apraksin’s retreat, saved Prussia from a situation which, after Kolín, had appeared desperate.