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."
João Carlos de Bragança (Duke de Lafões)
To get to Vienna, already with the Seven Year's War running, he enlisted in the Austrian army, where D. Manuel, Count of Ourém, his uncle, as well as of the king John V of Portugal, had been general. He was a superior officer of an Infantry Regiment of the Prince of Ligne, his relative, having participated in the last campaigns of the Seven Years ' War. After the end of the war, in February 1763, he decided to travel and has visited Switzerland, Italy, France, and the East, Greece and Egypt. He later visited Prussia and Poland. In 1766, it was proposed to integrate the Austrian army, with the rank of major-general, but the authorization of the Portuguese crown was never given. In 1770 Paride ed Elena by Gluck was dedicated to the Duke of Braganza, a specialist on mythology and music.