Austro-Prussian War
The pretext for the conflict was found in the dispute between Prussia and Austria over the administration of Schleswig-Holstein, which the two of them had conquered from Denmark and agreed to jointly occupy at the end of the Second Schleswig War in 1864. When Austria brought the dispute before the German Diet and also decided to convene the Diet of Holstein, Prussia declared that the Gastein Convention had thereby been nullified and invaded Holstein. When the German Diet responded by voting for a partial mobilization against Prussia, Bismarck claimed that the German Confederation was ended. Crown Prince Frederick "was the only member of the Prussian Crown Council to uphold the rights of the Duke of Augustenburg and oppose the idea of a war with Austria which he described as "fratricide"". Although he supported unification and the restoration of the medieval empire, "Fritz could not accept that war was the right way to unite Germany."
Seven Years' War
Frederick II of Prussia had received reports of the clashes in North America and had formed an alliance with Great Britain. 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.