Austro-Prussian War or Seven Weeks War, June 15–Aug. 23, 1866, between Prussia, allied with Italy, and Austria, seconded by Bavaria, Württemberg, Saxony, Hanover, Baden, and several smaller German states. It was deliberately provoked by Bismarck, over the objections of his king, in order to expel Austria from the German Confederation as a step toward the unification of Germany under Prussian dominance. The pretext for precipitating the conflict was found in the dispute between Prussia and Austria over the administration of Schleswig-Holstein. When Austria brought the dispute before the German diet and also decided to convene the Holstein diet, Prussia, declaring that the Gastein Convention (see under Gastein) had thereby been nullified, invaded Holstein. When the German diet responded by voting for a partial mobilization against Prussia, Bismarck declared that the German Confederation was ended. With an efficient military machine that amazed Europe, Prussia overran the German states allied with Austria and crushed (July 3) the Austrians at Sadová (or Sadowa; also known as the battle of Königgrätz), in E Bohemia. However, Bismarck had no intention of weakening Austria, a potential ally, more than necessary. The preliminary treaty of Nikolsburg (July 26) was followed (Aug. 23) by the Treaty of Prague. Against Italy, the Austrians had won victories on the land, at Custozza, and on the sea, at Lissa. Nevertheless, the peace treaty forced Austria to cede Venetia to Italy. Prussia, satisfied with the exclusion, acknowledged in the treaty, of Austria from German affairs, demanded no territory from Austria, but annexed Hanover, Hesse, Nassau, and Frankfurt, in addition to Schleswig-Holstein. The German Confederation was replaced by the Prussian-led North German Confederation. Thus the war paved the way for the establishment (1871) of the German Empire and the reorientation of Austria (reorganized in 1867 as the Austro-Hungarian Monarchy) toward the east. The moderate peace terms facilitated the Austro-German alliance of 1879.
See H. Friedjung, The Struggle for Supremacy in Germany, 1859–1866 (10th ed. abr., tr. 1935, repr. 1966); G. A. Craig, The Battle of Königgrätz (1964); E. A. Pottinger, Napoleon III and the German Crisis, 1865–66 (1966).