While the Franco-Prussian war was the final step towards German Unification, the Austro-Prussian war was probably the second most important single event in that process. As I have mentioned before, the Austro-Prussian war saw Prussia defeat the Empire of Austria in six weeks, thus supplanting it as the dominant power in Germany. The war began on June 14th, 1866, and ended on July 22nd 1866.
The pretext for Prussia’s declaration of war on Austria resulted from Austria’s joint occupation of the formerly Danish province of Schleswig-Holstein. Austria had allowed the estates of the duchies to call up electors for a united assembly, which Prussia declared, on January 26th, was in breach of their agreement. The following months saw the two sides mobilize their forces. In April Prussian Minister-President Otto von Bismarck made an alliance with Italy. The German Diet ordered a partial mobilization against Prussia on June 14th, thus beginning the war. Austria had more of the German states on its side, but Prussia’s alliance with the Kingdom of Italy drew Austrian troops south. Prussia sued the railroad to quickly move its troops to invade Saxony and Bohemia. There, the Austrian army was gathering its forces to invade Silesia, part of modern-day Poland that Austria had lost to Prussia over a century before. At the Battle of Sadowa, the numerically superior Austrians were outmaneuvered thanks in large part to the organizational work of Chief of Staff Leonhard Graf von Blumenthal. Further, Prussian infantry were armed with breach loading rifles, which were superior to the muzzle loading rifled muskets that Austrian troops were issued. Chief of General Staff Helmuth von Moltke commanded Prussian forces at that battle, and orchestrated the near complete destruction of the primary Austrian army. Austria’s German allies did relatively little in the war, with only Hanover ever defeating Prussia in the field. In Italy, Austria won a few battles but lost part of its Italian lands to invasion. On July 22nd, Prussia made peace with Austria, forcing Italy to seek an armistice on August 12th.
Although Austria herself lost very little land as a result of the Peace of Prague, the treaty that formally ended the war, its position in Germany collapsed just as Prussia’s rose. Prussia annexed most of Northern Germany and incorporated the rest into the North German Confederation the next year. It also signed defensive alliances with the states of Southern Germany. Austria lost all influence in Germany and was forced to cede Venice to Italy. This defeat led to the reform of the Empire to create Austria-Hungary. Prussia’s increase in power and influence would allow it to defeat France five years later, resulting in the formation of Germany under Prussian rule.