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."
Silesian Wars
After entering Bohemia, Prussian forces converged upon Prague by the beginning of September, seizing the city on 16 September. This new threat drew the Austrian army back from Alsace through Bavaria; the French, however, failed to harass and disrupt the Austrian redeployment, so Austria's army was able to return to Bohemia quickly and at full strength, though it was forced to abandon control of Alsace and Bavaria. Frederick gathered his forces around Prague and tried repeatedly to force a decisive engagement, but Austrian commander Otto Ferdinand von Traun focused on harassing the invaders' supply lines, eventually forcing the Prussians to abandon Prague and Bohemia and retreat into Upper Silesia in November.
With the January 1745 Treaty of Warsaw, Austria established a new "Quadruple Alliance" among Austria, Britain, Saxony, and the Dutch Republic, followed by a secret offensive alliance between Austria and Saxony, which envisioned a territorial partition of Prussia. Meanwhile, Emperor Charles died on 20 January, destroying the rationale behind Frederick's alliance. These events combined to produce a major shift in the direction of the war in Germany. Austria renewed its offensive against Bavaria in March 1745, decisively defeating the Franco-Bavarian army at the 15 April Battle of Pfaffenhofen, and making peace with Maximilian III of Bavaria (the son of the late Emperor Charles) by the Treaty of Füssen on 22 April.