The Franco-Prussian War - known in Germany as the German-French War (Deutsch-Französischer Krieg) or War of 1870/71, and in France as the Franco-German War (Guerre franco-allemande) or "Guerre franco-prussienne" - was the last of three wars that led to the unification of Germany (the first since the Holy Roman Empire had any political power).
There were multiple causes of the war, including but not limited to, a potential sale of Luxembourg to France, the vacancy of the Spanish throne, and the Prime Minister of Prussia modifying and publishing an insulting telegram about a meeting of the French Ambassador. For whatever cause, a dangerously underprepared France declared war on Prussia (and thus the North German Confederation) in July of 1870. These circumstances led the South German states (Bavaria, Baden, Württemberg) to join the side of the North German Confederation, thanks to a secret mutual defense treaty arranged by Bismark.
The result was a 10-month Curb-Stomp Battle as the Prussians decimated the French in all but three battles (where the French won one at Broney-Colombey and fought to a draw in two others), captured the French Emperor, Napoleon III, and unified Germany.
Another result of the war was Germany's annexation of Elsaß-Lothringen (Alsace-Lorraine), which they held until World War I. This would prove a pretty major mistake, as Alsace-Lorraine made France implacably hostile to Germany, as well as changing the international perception of Germany from victim to aggressornote . Moreover, the French had to leave Rome, indirectly finishing the Unification of Italy.
The defeat of Napoleon III led to his fall and the proclamation of the Third French Republic, which continued the war longer than the Germans expected by continually raising new armies even as Paris was besieged. In a bloody epilogue after the signing of the definitive peace treaty French fought French as the forces of the conservative central government put down the Paris Commune, a short-lived revolutionary government which was in control by revolutionary members of the French working class. While short-lived and petty by that time, it would inspire a book by Karl Marx (The Civil War in France) and later Vladimir Lenin to start the October Revolution and create Soviet Union, thus being responsible of communism's first steps as a major power through the 20th century.
By the end of the war, the balance of power in Europe had been completely upended, as France's centuries-long superiority over the rest of Europe was abruptly terminated. What had once been a chain of small and mid-size German states had, within a year, become the single most powerful nation on the continent. Even worse (from the French perspective), Germany was growing stronger, rapidly increasing its population and industry.
This in turn started a chain of events that led to World War I. France, desperate and humiliated, formed a series of alliances in case they ever went to war with Germany again, and Germany did the same. With one exception, all of these alliances became the Allied Powers (France, Great Britain, and Russia, as well as the other countries they gathered after the war began) and the Central Powers (Germany and Austria-Hungary, and the countries they gathered). The newly-united Italy was the exception - Italy was in an alliance with Germany, but didn't enter World War I until the Allied Powers offered them parts of the Austro-Hungarian Empire.
- Bombardement d'une maison (Bombing of a house, 1897), most probably the very first film to depict it (and probably the very first war film). It was directed by Georges Méliès (yes, that one)
- Several Guy de Maupassant short stories use the war as setting.
- Émile Zola's La Débâcle is set during the war, specifically at the Battle of Sedan and the French civil war in spring 1871.
- The short story The Street of The First Shell from The King in Yellow is set during the Siege of Paris.
- Henrik Ibsen was in Munich at the time, and wrote a long "rhyming letter" to a friend (included in his collected poems). The poem tells quite bluntly that he has had it with merry Prussians belching out Wacht am Rhein at every opportunity, and is quite pessimistic about the future of German militarism. Spot on.
- Sizable chunk of Victoria: An Empire Under the Sun will be about pouring vast amounts of time and resources either to bring the war or stop/postpone it. The outcome of the war is rather random in vanilla versions of first and second game, but gets brutally historical under expansion packs and mods.
- Norwegian author Nordahl Grieg wrote a full dramatic play: The Defeat, concerning the fate of the Paris commune. Grieg, being a communist, actually used the contemporary writings of Marx as source material. The Big Bad of the story is, of course, Thiers (while some of the communards are depicted as downright assholes as well). Downer Ending of historical accuracy: Kill 'Em All (including a number of children shot on stage).
- In the alternate history The Legacy of the Glorious, this war is known as the Hohenzollerns' War, after the reigning dynasty in Prussia (although in TTL's Spain it is called King Leopold's War). Like it happened in Real Life, the most direct cause of the war was the Ems dispatch, but there is a difference: since Leopold of Hohenzollern-Sigmaringen was confirmed as King of Spain before the French caught wind of it, France declares war on Prussia and Spain. War ends even more disastrously for the French, because, apart from Alsace-Lorraine, they also lose the southern department of Rousillon and the Oranesado in north Africa to Spain, as well as paying a greater war indemnization.