Seven Years' War: Frederick the Great defeats the allied armies of France and the Holy Roman Empire at the Battle of Rossbach.

The Battle of Rossbach took place on 5 November 1757 during the Third Silesian War (17561763, part of the Seven Years' War) near the village of Rossbach (Robach), in the Electorate of Saxony. It is sometimes called the Battle of, or at, Reichardtswerben, after a different nearby town. In this 90-minute battle, Frederick the Great, king of Prussia, defeated an Allied army composed of French forces augmented by a contingent of the Reichsarmee (Imperial Army) of the Holy Roman Empire. The French and Imperial army included 41,110 men, opposing a considerably smaller Prussian force of 22,000. Despite overwhelming odds, Frederick employed rapid movement, a flanking maneuver and oblique order to achieve complete surprise.

The Battle of Rossbach marked a turning point in the Seven Years' War, not only for its stunning Prussian victory, but because France refused to send troops against Prussia again and Britain, noting Prussia's military success, increased its financial support for Frederick. Following the battle, Frederick immediately left Rossbach and marched for 13 days to the outskirts of Breslau. There he met the Austrian army at the Battle of Leuthen; he employed similar tactics to again defeat an army considerably larger than his own.

Rossbach is considered one of Frederick's greatest strategic masterpieces. He crippled an enemy army twice the size of the Prussian force while suffering negligible casualties. His artillery also played a critical role in the victory, based on its ability to reposition itself rapidly responding to changing circumstances on the battlefield. Finally, his cavalry contributed decisively to the outcome of the battle, justifying his investment of resources into its training during the eight-year interim between the conclusion of the War of Austrian Succession and the outbreak of the Seven Years' War.

The Seven Years' War (1756–1763) was a global conflict between Great Britain and France for global pre-eminence. In Europe, the conflict arose from issues left unresolved by the War of the Austrian Succession (1740–1748), with Prussia seeking greater dominance. Long-standing colonial rivalries pitting Britain against France and Spain in North America and the Caribbean islands were fought on a grand scale with consequential results. In Europe, the war broke out over territorial disputes between Prussia and Austria, which wanted to regain Silesia after it was captured by Prussia in the previous war. Britain, France and Spain fought both in Europe and overseas with land-based armies and naval forces, while Prussia sought territorial expansion in Europe and consolidation of its power.

In a realignment of traditional alliances, known as the Diplomatic Revolution of 1756, Prussia became part of a coalition led by Britain, which also included long-time Prussian competitor Hanover, at the time in personal union with Britain. At the same time, Austria ended centuries of conflict by allying with France, along with Saxony, Sweden and Russia. Spain aligned formally with France in 1762. Spain unsuccessfully attempted to invade Britain's ally Portugal, attacking with their forces facing British troops in Iberia. Smaller German states either joined the Seven Years' War or supplied mercenaries to the parties involved in the conflict.

Anglo-French conflict over their colonies in North America had begun in 1754 in what became known in the United States as the French and Indian War, a nine-year war that ended France's presence as a land power. It was "the most important event to occur in eighteenth-century North America" prior to the American Revolution. Spain entered the war in 1761, joining France in the Third Family Compact between the two Bourbon monarchies. The alliance with France was a disaster for Spain, with the loss to Britain of two major ports, Havana in the Caribbean and Manila in the Philippines, returned in the 1763 Treaty of Paris between France, Spain and Great Britain. In Europe the large-scale conflict that drew in most of the European powers was centered on the desire of Austria (long the political centre of the Holy Roman Empire of the German nation) to recover Silesia from Prussia. The Treaty of Hubertusburg ended the war between Saxony, Austria and Prussia, in 1763. Britain began its rise as the world's predominant colonial and naval power. For a time France's supremacy in Europe was halted until after the French Revolution and the emergence of Napoleon Bonaparte. Prussia confirmed its status as a great power, challenging Austria for dominance within the German states, thus altering the European balance of power.