Seven Years War is the name given to to the European war which arose from the formation of a coalition between Austria, France, Russia, Sweden and Saxony against Prussia, with the object of destroying, or at least crippling, the power of Frederick the Great. Prussia was joined by England, and between England and France, as usual, a maritime and colonial war broke out at the first pretext; this war laid the foundations of the British empire. Before this war was fought in Europe, the French dominion in Canada and the French influence in India had almost entirely been overthrown by the victories of Clive, Amherst and Wolfe (see French and Indian War.) The steadfast resistance of Prussia, almost single-handed, laid the solid, if then unseen, foundations of modern Germany. Countless marches and maneuvers in the battles of Pirna, Prague, Kolin, Rossbach, Leuthen, Zorndorf, Kunersdorf and Minden and the equilibrium of forces in 18th-century warfare is a source for study of military history.

Learning of the existence and intentions of the coalition against him, Frederick determined to strike first and adroitly dispersed portions of his 150,000 man force along the frontiers of Pomerania, Russia and Silesia while maintaining a main body of 70,000 in three columns ready to advance into Saxony. On August 29, 1756 the Saxon frontier was crossed and the surprised Saxon army of 14,000 fell back to the entrenched camp of Pirna, an almost inaccesible plateau parallel to the Elbe and close to the Bohemian frontier. The secret of the Prussian intentions had been so well kept that the Austrians were still widely distributed in Bohemia and Moravia. Leaving detachments to watch the exits from Pirna, the Prussians moved up the Elbe and took post at Aussig to cover the investment of the Saxons. The two armies met at Lobositz (opposite Leitmeritz) on the morning of October 1. The battle began in a thick fog, rendering dispositions very difficult, and victory fell to the Prussians, principally owing to the tenacity displayed by their infantry in a series of disconnected local engagements. The nature of the ground rendered pursuit impossible, and the losses were approximately 3,000 men each, but the overall results sealed the fate of the Saxons who surrendered on October 14, and were taken over bodily into Prussian service.

The coalition had undertaken to provide 500,000 men against Prussia but by the beginning of the year Austria had only 132,000 ready for action in nothern Bohemia. Frederick was organizing 250,000 with 45,000 subsidized by England and posted to cover Hanover from a French attack. After leaving detachments to guard his other frontiers, Frederick was able to take the field out of Saxony with nearly 150,000 men. Frederick's surprise attack had virtually leveled the field for a lengthy war.

When the Seven Years War broke out with the Prussian invasion of Saxony eight years had elapsed since the Peace of Aix-la-Chapelle, 1748, which concluded the War of Austrian Succession. During the years 1754 and 1755 the French performed a number of hostile acts against the British on land and sea in various parts of the world to which the British retaliated, especially in the Mediterranean and along the frontier between French Canada and British America. Thus there existed during those two years a state of affairs which can be best described as an unofficial war of outposts between the British and French.

The preliminaries of the peace of Paris were signed on November 3, 1762 with the formal conclusion signed in 1763.