The lead-up to the Seven Years' War began in the years after the War of the Austrian Succession, which ended in 1748. The war ended with the Prussian seizure of Silesia being affirmed by the Treaty of Aix-la-Chapelle and Charles VII of Bavaria recognized as the Holy Roman Emperor. After the war's end Charles set about securing the House of Wittlesbach's continued alliance to the House of Habsburg, and thus secured his successors as the successors to the Holy Roman Imperial throne. The rivalry between Austria and Prussia continued to grow and in 1756 the British and Prussians officially signed an alliance after the British government recognized that Austria would be not a good ally in fighting the French after their failure to do so in the previous conflict. Austrians then turned to their old enemy, the French, and themselves signed an alliance in 1756, which the Austrians followed by forming an anti-Prussian alliance with Russia. The Russians also set their sights on Swedish territory in Finland, and had begun to build up their navy in order to try and establish dominance over the Baltic Sea. The Kingdom of Naples and Sicily, ruled by the Bourbon King Charles V, meanwhile, was also making plans for another war with its rival, the Kingdom of Sardinia, now with the possibility of Austrian assistance. The British also formally extended their alliance to the Electorate of Hanover under Georg August, establishing the battle lines that would come to define the two sides in the coming war.
Meanwhile abroad the two main colonial powers, the French and the British, had already begun the path to war by pressing rival claims to the Ohio Valley. This climaxed in a British expedition led by a young commander named George Washington, who ambushed a group of French and Native American soldiers, and thus sparked the French and Indian War in 1754. The intervening two years between the start of the French and Indian War and the opening of hostilities in Europe saw the a build-up of military power among the many major powers of the continent, with the British government focusing primarily on naval power while their Dutch allies focused on building up land forces along their French border. Colonial forces had also begun clashing in the increasingly-crowded subcontinent of India, where the French and British had been fighting sporadically since 1746, and the British were increasingly growing their power over the area and the French-allied Mughal Empire. As war approached in Europe, the Prussians become increasingly hostile to their southern neighbor Saxony and the Austrians, but knew that a war on three fronts would be unsuitable regardless of the situation if they had to fight the French in the West, the Austrians, Saxons, and Bavarians in the South, and the Russians in the East. Only the ambivalence of the Swedes, still allied with the British, would save them from fighting a war in every direction, and with some confidence the Prussians began major hostilities in the Fall of 1756.