Franco-Prussian War
The Franco-Prussian War was a war between France and Prussia. Some German allies of Prussia also joined. This war was 'designed' by Otto von Bismarck , the Prussian Chancellor (senior politician). He wanted to unite the 39 small German states (countries) by making them fight together against a common enemy. Bismarck did this by irritating the Emperor of France, Louis-Napoléon Bonaparte (Napoleon III). The war started when France declared war on 19 July 1870. It ended on 10 May 1871. Prussia won this war.
Causes
The causes of the Franco-Prussian War are mostly due to France being nervous of a Protestant country on their border. While France had helped Prussia beat Austria in the Austro-Prussian War (1866), France would not let the North and South German states unify. In 1869, the throne of Spain was offered to a prince of the Catholic branch of the Prussian Hohenzollern royal family.
France found out about the offer, and demanded that Prussia reject it, since France did not want two Prussia-friendly states on both their land borders. The prince said no, but the French wanted Prussia to say no also. The Prussian King Wilhelm I sent the Ems telegram assuring the French Emperor, Napoleon III, that the prince would not become king of Spain. Otto von Bismarck, the Chancellor of Prussia, publicly released a version that he edited or doctored to make it seem that his king had insulted the emperor's ambassador. This was part of his plan to unify the German states. The two sides exchanged angry words, France declared war, and in July 1870 the war started with Prussia fully supported by the South German states.
Results
With her German allies and universal conscription, Prussia was able to bring together a bigger army than the French. The Prussian army's weapons, training and leadership were better, too. For example, the Prussian General Staff were very well organized and the army had modern equipment like the Dreyse needle gun and Krupp artillery (heavy-duty guns). They won the war. Notable victories include Sedan, Mars-la-Tour, Gravellote, and Metz. French Republicans overthrew the Second French Empire and made peace.
After this war, France had to give Prussia some mainly German speaking regions previously under French control. These were the provinces of Alsace and Lorraine. Prussia took steps to unite the independent German states into one country, the German Empire. The historical term for this is the Unification of Germany.