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
The Saxon and Austrian armies were unprepared, and their forces were scattered. Frederick occupied Dresden with little or no opposition from the Saxons. At the Battle of Lobositz on 1 October 1756, Frederick prevented the isolated Saxon army from being reinforced by an Austrian army under General Browne. The Prussians then occupied Saxony; after the Siege of Pirna, the Saxon army surrendered in October 1756, and was forcibly incorporated into the Prussian army. The attack on neutral Saxony caused outrage across Europe and led to the strengthening of the anti-Prussian coalition. The only significant Austrian success was the partial occupation of Silesia. Far from being easy, Frederick's early successes proved indecisive and very costly for Prussia's smaller army. This led him to remark that he did not fight the same Austrians as he had during the previous war.