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."
Treaty of Hubertusburg
Austria's resolve to repossess the rich province of Silesia, which had been lost to Prussia in 1748, was the major conflict leading to the Seven Years' War. Maria Theresa, Archduchess of Austria and Queen of Hungary and Bohemia, acquired the support of Russia, Sweden, Saxony, Spain, and France, with the specific aim of waging war against Prussia and its ally, Great Britain. It was King Frederick the Great of Prussia, however, who initiated the hostilities with his attack and capture of Saxony in 1756.