The Anglo-Prussian Alliance was a military alliance created by the Westminster Convention between Great Britain and Prussia that lasted formally between 1756 and 1762, during the Seven Years' War. The alliance allowed Britain to concentrate most of its efforts against the colonial possessions of the French-led coalition while Prussia was bearing the brunt of the fighting in Europe. It ended in the final months of the conflict, but strong ties between both kingdoms remained.

On 29 August 1756, he led Prussian troops across the border of Saxony, one of the small German states in league with Austria. He intended this as a bold pre-emption of an anticipated Austro-French invasion of Silesia. He had three goals in his new war on Austria. First, he would seize Saxony and eliminate it as a threat to Prussia, then use the Saxon army and treasury to aid the Prussian war effort. His second goal was to advance into Bohemia, where he might set up winter quarters at Austria's expense. Thirdly, he wanted to invade Moravia from Silesia, seize the fortress at Olmütz, and advance on Vienna to force an end to the war.