Although the Seven Years' War was a global conflict, it took a specific intensity in the European theater based on the recently concluded
War of the Austrian Succession (1740–1748). The 1748
Treaty of Aix-la-Chapelle gave
Frederick II of Prussia, known as Frederick the Great, the prosperous province of
Silesia. Empress
Maria Theresa of Austria had signed the treaty to gain time to rebuild her military forces and forge new alliances; she was intent upon regaining ascendancy in the
Holy Roman Empire as well as recovering the Silesian province. In 1754, escalating tensions between Britain and France in
North America offered France an opportunity to break the British dominance of Atlantic trade. Seeing the opportunity to regain her lost territories and to limit Prussia's growing power, Austria put aside its old
rivalry with France to form a new coalition. Britain aligned herself with the
Kingdom of Prussia; this alliance drew in not only the British king's European territories held in
personal union, including Hanover, but also those of his relatives in the
Electorate of Brunswick-Lüneburg and the
Landgraviate of Hesse-Kassel. This series of political maneuvers became known as the
Diplomatic Revolution. At the outset of the war, Frederick had one of the finest armies in Europe: his troops could fire at least four volleys a minute, and some of them could fire five. By the end of 1757, the course of the war had gone well for Prussia, and poorly for Austria. Prussia achieved spectacular victories at
Rossbach and
Leuthen, and reconquered parts of Silesia that had fallen to Austria. The Prussians then pressed south into Austrian
Moravia. In April 1758, Prussia and Britain concluded the
Anglo-Prussian Convention in which the British committed to pay Frederick an
annual subsidy of £670,000. Britain also dispatched 7,000–9,000 troops to reinforce the army of Frederick's brother-in-law, the
Duke Ferdinand of Brunswick-Wolfenbüttel. Ferdinand evicted the French from Hanover and
Westphalia and re-captured the port of
Emden in March 1758; he crossed the Rhine, causing general alarm in France. Despite Ferdinand's victory over the French at the
Battle of Krefeld and the brief occupation of
Düsseldorf, successful maneuvering of larger French forces required him to withdraw across the Rhine. While Ferdinand kept the French occupied, Prussia had to contend with Sweden, Russia, and Austria. There remained a possibility that Prussia could lose Silesia to Austria,
Pomerania to Sweden, Magdeburg to Saxony, and
East Prussia to Poland or
Russia: for Prussia, this represented an entirely nightmarish scenario. By 1758, Frederick was concerned by the Russian advance from the east and marched to counter it. East of the
Oder river in Brandenburg-
Neumark, a Prussian army of 35,000 men fought a Russian army of 43,000 at the
Battle of Zorndorf on 25 August 1758. Both sides suffered heavy casualties but the Russians withdrew, and Frederick claimed victory. At the
Battle of Tornow a month later, a Swedish army repulsed the Prussian army but did not move on Berlin. By late summer, fighting had reached a draw. None of Prussia's enemies seemed willing to take the decisive steps to pursue Frederick into Prussia's heartland. ==Prelude==