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."
Austro-Hungarian Armed Forces
Prussia established its domination over other German states by its victory over Austria in the Seven Weeks' War in 1866. The critical battle was waged at Königgrätz (Hradec Králové in the present-day Czech Republic). The Austrians armed with muzzle-loading rifles sustained 20,000 casualties and lost 20,000 prisoners. The battle overshadowed Austria's victories over Prussia's Italian allies at Custoza and in the naval Battle of Lissa (Vis) off the Dalmatian coast in which a smaller Austrian fleet of ironclads overcame the Italians by ramming them. Following the end of the Seven Weeks' War, Austria experienced fifty years of peace until World War I broke out in 1914.