Why France Declared War in 1870

France declared war on Prussia on July 19, 1870 because of a need to have glory and to establish the Bonaparte name as legitimate. Glory was represented through the attempts and denial of the annexation of Luxembourg. France tried for both glory and legitimacy with its interaction with Prussia about the Spanish throne. Napoleon III's declaration of war was for his legitimacy and an attempt to obtain glory for France.

The attempt to obtain Luxembourg at the end of the Austro-Prussian War was primarily for glory. Prussia hinted to France that they would receive something if they would not act upon their alliance with Austria and stay out of the war. France saw this as an opportunity to stay out of the way since they were already involved in Mexico at the time and were struggling to keep control of the situation because the Americans unofficially jumped in to help once their Civil War ended. As France tried to take care of this problem, they did not have enough manpower to assist Austria. This made them take advantage of Prussia's offer since they would still get some spoils from the war, even though they were not involved in it.

France thought they would get something out of the war since they announced that they would receive reparation from every war in Europe that they did not involve themselves in. This was a pompous thing for the French to claim because they did not have the right nor the power to enforce this policy because they were already involved elsewhere in the world. France put this policy into effect for glory. They wanted to look as though they were on top of things and had power and influence over what other countries did. From this policy came France's demand for Luxembourg at the end of the Austro-Prussian War. France wanted Luxembourg because it was a tiny German state that was close to the French border. France believed they would get it because of their foreign policy and Prussia had hinted that France would get something if they were not involved in the war. If France had gotten Luxembourg it would have been a boost to the glory of France because it would show that France was a supreme power that other countries had to listen to. However, Prussia did not let France have Luxembourg because there had been no formal agreement. This was a sting to French glory because Prussia had made a fool out of France and France had not helped Austria, an ally in need. This caused the French to demand glory and revenge from the Prussians, which helped pave the way for the declaration of war in 1870.

The interactions between France and Prussia regarding the Spanish throne were French attempts at both glory and legitimacy for the Bonaparte name. The Prussians tried to put Prince Leopold of Hohenzollern on the Spanish throne. This was because the line of succession to the Spanish throne had developed genetic problems, which made them unable to effectively rule the country. This meant that Spain was in search of a new royal family. The Prussians tried to put Leopold on the throne because they wanted to eventually unite the Spanish and Prussian thrones, so that one large kingdom would be formed. France did not like this idea because it would mean that they would be surrounded by two large powers and would most likely be squeezed out from in between. France made Prussia back down, through diplomatic means, and agree not to put Leopold on the throne again. This gave France glory because they showed that they were still up in the ranks with all of the other big powers. It also helped Napoleon III gain some ground in the direction of legitimacy because he helped win a diplomatic victory for France. The French were so anxious to make the most of this diplomatic victory that Gramont made Napoleon III send Benedetti to give the king of Prussia a telegram, which later became known as the Ems telegram. If the victory had been greater, it would have helped gain even more glory for France and it would have assisted Napoleon III in his journey for legitimacy and regaining the popularity he had lost during the Mexican Adventure. The Ems telegram asked the king to put in writing that he would never try to place anyone on the throne of Spain. The message contained underlying threats that if the King did not write a formal apology and promise to France, then France would attack Prussia. The king would not do this, and his advisor, Bismarck, asked for a copy, which he edited and published as a veiled threat from the French. The publication of the telegraph enraged the Prussians because they saw it as a threat to their greatness. The Prussians did not like being bossed around by the French. This attempt by the French to gain more glory and legitimacy for Napoleon III failed.

Since the previous attempts to get glory and legitimacy failed, Napoleon III needed to regain both of these in order to keep the government stable, which forced him to declare war on Prussia. Napoleon III knew that since he did not have legitimacy he needed glory to keep himself in power. If he failed too many times, the people would simply overthrow him because there was no reason to keep an illegitimate leader in power if he was not doing good for the country by bringing it glory. Napoleon III had already had a defeat in Mexico and an embarrassment when Prussia did not give France Luxembourg as France expected. This meant he could not afford to mess up again, otherwise he would be out of a job. Since Napoleon III needed glory to stay in power, he was forced to declare war on Prussia since he could not afford even a diplomatic defeat. By declaring war on Prussia on July 19, 1870, he started the Franco-Prussian War of 1870.

The Franco-Prussian War of 1870 started because of a need for both glory and legitimacy. Napoleon III was not a legitimate leader, since he was not a member of the Bourbon nor the Orleanist family, which meant he needed glory in order to ensure that he stayed in power. He also wanted to try to establish the Bonaparte name as legitimate so that his relatives could rule France. These were the two motives for declaring war. France was in need of glory because of earlier failures in Mexico and with Luxembourg. France fleetingly obtained glory with its diplomatic victory over Prussia regarding the Spanish succession, but the French overplayed this win and turned it into a defeat. This put Napoleon III into a position where he had to declare war on Prussia for there to be any hope for glory and his own legitimacy, which caused the war.