Franco-prussian War: Causes, Development And Consequences

The Franco-Prussian War was a warlike conflict between the Second French Empire, under the command of Napoleon III, and Prussia and its allies, the North German Confederation and the kingdoms of Baden, Bavaria and Württemberg. It is considered the most important event in Europe between the Napoleonic wars and the First World War .

The war between both powers officially began on July 19, 1870 and lasted until May 10, 1871. The conflict ended with the French defeat, causing the fall of the imperial regime and the advent of the Third Republic.

Franco-Prussian War

The tension between the two countries had grown enormously due to the Prussian claims to unify the Germanic territories and the Gallic attempts to prevent it. Likewise, Napoleon III had his own expansionist intentions, such as his interest in annexing Luxembourg.

The final excuse for the beginning of the military operations came with the vacancy to the Spanish kingdom. The Crown was offered to a German, sparking French opposition. The manipulation of a telegram on the subject by Chancellor Bismarck, favorable to the war, was the last push towards the conflict.


The most distant antecedents of this war must be sought in the redistribution of the balance of power that led to the victory of Prussia over Austria at the beginning of the 19th century. In the subsequent Congress of Vienna, Chancellor Otto Von Bismarck succeeded in expanding Prussian rule over much of Central Europe.

For its part, France tried not to lose its continental influence in the face of the growing power of its neighbor. Already in 1868 a war was about to break out, after the customs union that Prussia established with its allies

In short, everyone was waiting for the right moment to settle the dominance of the continent using weapons. Prussia hoped seeking to create a national sentiment that would promote the unification of nearby territories; France wanted to finalize the modernization of its army.

French concerns and pretensions

The Second French Empire had been born in 1851 when Napoleon III staged a coup that brought him to power. It was an absolutist regime and met great opposition from part of society.

Within the foreign policy of the ruler was the opposition to Prussia increasing its power. Already in 1866 she was totally against a possible union between Prussia and other German states. She even mobilized the army to stop that option.

On the other hand, Napoleon III showed his claims to annex Luxembourg, among other small territories. It did not do so due to the lack of international support.

The atmosphere of the court was clearly anti-Russian. To this must be added the loss of prestige that was the result of the Second French Intervention in Mexico and the pressure from the most nationalist sectors.

The Spanish throne

The spark that ended up starting the conflict took place in Spain. The abdication of Queen Elizabeth II had vacated the throne and Parliament offered the position to Prince Leopold of Hohenzollern-Sigmaringen, a cousin of the King of Prussia, William I Hohenzollern.

France reacted by opposing this appointment, which would have meant a great increase in Prussia’s influence in Europe. Pressure from Napoleon III seemed to work, and Leopold rejected the offer.

However, France did not trust that resignation. Therefore, she sent her ambassador to Bad Ems, where King William I spent her holidays. The objective was that this leave in writing the definitive rejection of the Spanish throne.

The Ems Telegram

Historians describe the meeting between the Prussian king and the French ambassador as very tense. The monarch did not want to accept the requests of the French government to guarantee that Leopoldo or another relative would never accept the Spanish offer.

Guillermo I sent a telegram to his chancellor Bismarck informing of the result of the meeting. This, seemingly harmless, gave Bismarck, a supporter of war, the perfect tool to provoke it.

In this way, the chancellor sent his own version of the telegram to the press, changing the content enough to imply that the French envoy had been deeply humiliated and thus infuriating Napoleon III. The latter fell into the trap and on July 19, 1870, declared war on Prussia.

Development of the war

By the time the war started, France had finished modernizing its army. It had 400,000 men and was considered the best in the world. However, the training of the reservists had been very limited.

On the contrary, the Prussians had indeed trained their men very professionally. Among their line troops, the militias and the reservists, they numbered almost 1 million men who could enter combat almost immediately. Also, their communications infrastructure was much better.

Beginning of the conflict

The state of war was declared on July 19, 1870. Poor French logistics meant that it could only mobilize about 288,000 soldiers.

For their part, the Prussians were supported by the southern Germanic states, so their forces were expanded, mobilizing 1,183,000 men in a few days. By July 24 they had been deployed between the Rhine and Moselle rivers, leaving enough soldiers behind them in case of an invasion attempt from the Baltic Sea.

French reverse

The French strategy was to try to enter Prussian territory as soon as possible. However, they soon began to suffer defeats. The situation was the opposite of what they were looking for and, in a few weeks, hostilities were resolved in France.

The only thing that worked on the French side was irregular warfare. Groups of partisans harassed the Prussian troops continuously, although its overall effect was not too significant.

The German advance forced the French troops to retreat to Sedan, in the north of the country. The Prussian army pursued them and surrounded the area.

Battle of Gravelotte

One of the most important battles during this period was fought at Gravelotte. It is considered one of the crucial moments of the conflict, since the French defeat left them practically without options to win the war.

Despite the fact that the French side presented its best troops under the command of Marshal Bazaine, the Prussian maneuver surprised them by its speed and efficiency.

The two armies were only separated by the Meuse River and the Prussians decided to attack early in the morning. To achieve this, they built a floating bridge overnight and managed to defeat the enemy.

Battle of sedan

If the previous battle was important, that of Sedan was fundamental for the final result and for the fate of France.

Marshal Bazaine had been taken prisoner at Gravelotte and his army withdrew to Metz. The rest of the army, under the command of Napoleon III himself, set out to free Bazaine. The strategy failed and the Prussians besieged the French with 150,000 men.

The battle took place between September 1 and 2, 1870. Despite attempts to break through the encirclement, the Germans resisted. In the end, 83,000 French soldiers surrendered. Furthermore, Napoleon III was captured by the Prussians, which brought about the end of the Second French Empire.

The siege of Paris

Although Napoleon’s taking prisoner did not end the war, it did end his regime. As soon as the news reached Paris, the population rose to proclaim the Third Republic. A Government of National Defense was appointed, with General Louis Jules Trochu at the head.

For his part, Bismarck wanted the surrender to be swift and ordered his troops to besiege the French capital. On September 20 that siege had been completed.

The new French government was in favor of a surrender, but with not too harsh conditions. However, the Prussian demands were unaffordable: the surrender of Alsace, Lorraine and some fortresses on the frontier.

This caused France to try to continue the conflict, although it had no chance of success. The few battles that followed always ended with German victories.

End of the war

After some time, the result of the siege of Paris began to affect its inhabitants. Several famines followed one another due to lack of food, so, despite popular opposition, the National Defense Government decided to surrender and negotiate the terms of defeat.

The French and Prussian envoys met at Versailles to agree on a surrender treaty and its consequences. France was forced, before even beginning to negotiate, to hand over several vital fortresses for the defense of its capital. In any case, with no options, they had to accept Bismarck’s proposals.

Only part of the Parisians tried to maintain the defense. In March 1871 they took up arms and created a revolutionary government: the Paris Commune.

Consequences of war

In general terms, several consequences of this conflict can be pointed out. These include the end of the Second French Empire, the fall of Napoleon III and the lack of impediments to German unification.

The treaty of Frankfurt

Negotiations between winners and losers culminated in the signing of the Frankfurt Treaty on May 10, 1871. Its clauses included the passage of the provinces of Alsace and Lorraine into German hands.

In addition, France was forced to pay a large war indemnity, which amounted to five billion francs. Until he had paid the total, the Treaty established that German troops should remain in northern France. They stayed there for 3 years. The only thing the French achieved was that 100,000 prisoners were released.

Born in II Reich

For the Prussians, the greatest achievement of this war was in the political sphere, rather than the war. Thus, on January 18, 1871, even during the conflict, William I was proclaimed Emperor of Germany at Versailles itself and the Second German Empire or II Reich was declared. Unification was much closer.

An indirect consequence of the Franco-Prussian War was Italian unification. The French were not in a position to defend the papal territory of Rome, so it was annexed to Italy and made its capital.


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