Franco-Prussian War: The siege of Paris begins. The city held out for over four months before surrendering.

The Franco-Prussian War, occasionally known as the Franco-German War, and sometimes referred to in France as the War of 1870, was a conflict between France and the North German Confederation led by Prussia. Lasting from 19 July 1870 to 28 January 1871, the conflict was caused primarily by France's determination to reassert its dominant position in continental Europe, which appeared in question following the decisive Prussian victory over Austria in 1866.