Unification of Germany

After Napoleon's fall, the Congress of Vienna (1815) did not create a unified German state but a German Confederation of 39 sovereign states, dominated by Austria and Prussia. National feeling nevertheless grew, carried by students and liberals, while the economy drew the German states closer together: the Zollverein customs union, which came into force in 1834 under Prussian leadership, brought most of them together, without Austria. In 1848, an elected parliament met in Frankfurt, drew up a constitution and offered the imperial crown to King Frederick William IV of Prussia, who turned it down in the spring of 1849. Unification by the liberal, parliamentary route had failed.

In 1862, King Wilhelm I, in conflict with the Prussian House of Representatives over army reform, appointed Otto von Bismarck Minister-President. Bismarck governed without an approved budget and declared that the great questions of the day would be decided not by speeches and majority votes but “by iron and blood”. The opportunity came from the duchies of Schleswig and Holstein, ruled by the King of Denmark: on 1 February 1864, Prussian and Austrian armies entered Schleswig. After the storming of the Dybbøl redoubts on 18 April, the Treaty of Vienna of 30 October forced Denmark to cede Schleswig, Holstein and Lauenburg, which were placed under the joint administration of the two victors.

This joint administration soon became a source of conflict between the two powers. Allied with Italy, Bismarck provoked a war in June 1866 against Austria, which was backed by Bavaria, Saxony, Hanover and several other German states. Thanks to the needle gun and the railways, the Prussians crushed the Austrian army at Königgrätz (Sadowa), in Bohemia, on 3 July 1866. The Peace of Prague of 23 August dissolved the German Confederation and excluded Austria from German affairs; Prussia annexed Hanover, Hesse-Kassel, Nassau, Frankfurt and Schleswig-Holstein. North of the Main, it founded the North German Confederation, whose constitution came into force on 1 July 1867, with Bismarck as its chancellor; the southern states remained independent but were bound to Prussia by secret military alliances.

The final stage came through war with Napoleon III's France, alarmed by Prussia's growing power. In July 1870, the candidacy of a Hohenzollern prince for the Spanish throne sparked a diplomatic crisis. Bismarck published a shortened version of the Ems Dispatch of 13 July, worded to appear insulting, and France declared war on 19 July. The southern states sided with Prussia. Defeated in Alsace and Lorraine, the French army surrendered at Sedan on 2 September 1870; Napoleon III was taken prisoner and the Republic was proclaimed in Paris two days later. During the siege of Paris, treaties concluded in November with Bavaria, Württemberg, Baden and Hesse brought the southern states into the new union, and on 18 January 1871 Wilhelm I was proclaimed German Emperor in the Hall of Mirrors at the Palace of Versailles.

The Treaty of Frankfurt, signed on 10 May 1871, forced France to cede Alsace, except Belfort, and part of Lorraine, and to pay an indemnity of five billion francs. The German Empire, which brought together 25 states under Prussian dominance, was a federal state with a Reichstag elected by universal male suffrage, but the chancellor answered only to the emperor. Founded without Austria, it became within a few decades the leading industrial power of continental Europe. The annexation of Alsace-Lorraine fuelled a desire for revenge in France that weighed on Franco-German relations until the First World War.