Also called Franco-German War, was a war between France on the one hand and Northern German Federation and the south German states on the other hand in 1870-71. The German Chancellor Bismarck tricked the French Emperor, who needed a foreign politic success badly, in order to ease domestic tensions, into declaring war on the 19th. of July 1870, with what later became known as the Ems Dispatch.

Due to more efficient mobilization, as well as superior artillery, the German troops were able to take the French forces by surprise and defeat them encirclement battles. In one of these, the battle of Sedan, emperor Napoleon III. was captured. French resistance was carried on against the odds by the new government of national defense, which assumed power in Paris on September 4, 1870, and proclaimed the deposition of the emperor and the establishment of the Third Republic. Fifteen days later the Germans started to siege Paris. In the wake of the newly formed French forces beaten by the German Army, Paris surrendered.

As a consequence of the German victory, on 18 January, 1871 Willhelm I., king of Prussia was proclaimed as German Emperor in the Palace of Versailles and Germany was unified. The German Empire became the strongest power on the continent("half-hegemonic position").