Causes
The causes of the Franco-Prussian War are deeply rooted in the events surrounding the balance of power in Europe after the Napoleonic Wars. France and Prussia had been combatants, with France on the losing side and Napoleon I exiled to St. Helena. The war was increasingly likely as France would not tolerate its gradual loss of status and geopolitical advantage due to Prussia's increasing influence in Germany. As Otto von Bismarck noted, after being forced to resign from the role of Chancellor a generation after the war, "I knew that a Franco-Prussian War must take place before a united Germany was formed." French Emperor Napoleon III and Prime Minister Émile Ollivier's eagerness to relieve France from internal political convulsions also contributed to France's declaration of war on Prussia.
In addition, Otto von Bismarck goaded the French into declaring war by altering a telegram sent by William I. Releasing the Ems Telegram to the public, Bismarck made it sound as if the king had treated the French envoy in a demeaning fashion. Six days later, France declared war on Prussia.
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