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."
War of the Bavarian Succession
Count Karl-Wilhelm Finck von Finckenstein, Frederick the Great's prime minister, believed that any Austrian acquisition in Bavaria would shift the balance of power in the Holy Roman Empire, diminishing Prussia's influence. Prussia's recent gains had been hard-won: thirty years earlier, Frederick had engaged in protracted wars in Silesia and Bohemia, resulting in Prussia's annexation of most of Silesia, and now, with the economy and society modernizing under his direction, Prussia was emerging as a world power. In the Silesian Wars and the Seven Years' War, Frederick had earned a new, if grudging, respect for his kingdom's military and diplomatic prowess from the European powers of France, Russia, Britain and Austria. To protect Prussia's status and territory, Finck and Frederick constructed an alliance with the Electorate of Saxony, ostensibly to defend the rights of Charles II August, Duke of Zweibrücken.