Lasting from 19 July 1870 to 28 January 1871, the conflict was caused primarily by France's determination to reassert its dominant position in continental Europe, which appeared in question following the decisive Prussian victory over Austria in 1866.

A series of hard-fought Prussian and German victories in eastern France, culminating in the Siege of Metz and the Battle of Sedan, resulted in the capture of the French Emperor Napoleon III and the decisive defeat of the army of the Second Empire; a Government of National Defense was formed in Paris on 4 September and continued the war for another five months.

Resentment over the French government's handling of the war and its aftermath triggered the Paris Commune, a revolutionary uprising which seized and held power for two months before its suppression; the event would influence the politics and policies of the Third Republic.

This aim was epitomized by Prussian Chancellor Otto von Bismarck's later statement: "I did not doubt that a Franco-German war must take place before the construction of a United Germany could be realised.

Many in his court, such as Empress Eugénie, also wanted a victorious war to resolve growing domestic political problems, restore France as the undisputed leading power in Europe, and ensure the long-term survival of the House of Bonaparte.

A national plebiscite held on 8 May 1870, which returned results overwhelmingly in favor of the Emperor's domestic agenda gave the impression that the regime was politically popular and in a position to confront Prussia.

The leader of the monarchists in Parliament, Adolphe Thiers, spoke for moderation, arguing that France had won the diplomatic battle and there was no reason for war, but he was drowned out by cries that he was a traitor and a Prussian.

[40] Recruitment and organisation of the various armies were almost identical, and based on the concept of conscripting annual classes of men who then served in the regular regiments for a fixed term before being moved to the reserves.

[48] On 28 July 1870 Napoleon III left Paris for Metz and assumed command of the newly titled Army of the Rhine, some 202,448 strong and expected to grow as the French mobilization progressed.

As Austria, along with Bavaria, Württemberg, and Baden were expected to join in a revenge war against Prussia, I Corps would invade the Bavarian Palatinate and proceed to "free" the four South German states in concert with Austro-Hungarian forces.

[54] While the French hailed the invasion as the first step towards the Rhineland and later Berlin, General Edmond Le Bœuf and Napoleon III were receiving alarming reports from foreign news sources of Prussian and Bavarian armies massing to the southeast in addition to the forces to the north and northeast.

He told General Abel Douay, commander of the 2nd Division, on 1 August that "The information I have received makes me suppose that the enemy has no considerable forces very near his advance posts, and has no desire to take the offensive".

This battle saw the unsupported division of General Douay of I Corps, with some attached cavalry, which was posted to watch the border, attacked in overwhelming but uncoordinated fashion by the German 3rd Army.

The Emperor was a captive and the Empress in exile, but there had been no abdication de jure and the army was still bound by an oath of allegiance to the defunct imperial regime; on the other hand, the Government of National Defence had no electoral mandate.

[81] The republic then renewed the declaration of war, called for recruits in all parts of the country, and pledged to drive the German troops out of France by a guerre à outrance ('overwhelming attack').

Bismarck met Favre on 18 September at the Château de Ferrières and demanded a frontier immune to a French war of revenge, which included Strasbourg, Alsace, and most of the Moselle department in Lorraine, of which Metz was the capital.

Bismarck's demand that France surrender sovereignty over Alsace caused a dramatic shift in that sentiment in Italy, which was best exemplified by the reaction of Garibaldi soon after the revolution in Paris, who told the Movimento of Genoa on 7 September 1870 that "Yesterday I said to you: war to the death to Bonaparte.

This success was achieved despite the fact that the military industry and warehouses were concentrated mainly in Paris; all supplies in the province—chiefs, weapons, camps, uniforms, ammunition, equipment, baggage—had to be improvised anew.

Dispatched from Paris as the republican government emissary, Léon Gambetta flew over the German lines in a balloon inflated with coal gas from the city's gasworks and organized the recruitment of the Armée de la Loire.

In a final attempt to cut the German supply lines in northeast France, Bourbaki's army marched north to attack the Prussian siege of Belfort and relieve the defenders.

[93] Facing annihilation, the last intact French army of 87,000 men (now commanded by General Justin Clinchant)[94] crossed the border and was disarmed and interned by the neutral Swiss near Pontarlier (1 February).

Another group of three ministers arrived in Bordeaux on 5 February and the following day Gambetta stepped down and surrendered control of the provincial armies to the Government of National Defence, which promptly ordered a cease-fire across France.

[101] To relieve pressure from the expected German attack into Alsace-Lorraine, Napoleon III and the French high command planned a seaborne invasion of northern Germany as soon as war began.

The French railway system, with competing companies, had developed purely from commercial pressures and many journeys to the front in Alsace and Lorraine involved long diversions and frequent changes between trains.

[citation needed] Although Austria-Hungary and Denmark had both wished to avenge their recent military defeats against Prussia, they chose not to intervene in the war due to a lack of confidence in the French.

Napoleon III also failed to cultivate alliances with the Russian Empire and the United Kingdom, partially due to the diplomatic efforts of the Prussian chancellor Otto von Bismarck.

Bismarck had bought Tsar Alexander II's complicity by promising to help restore his naval access to the Black Sea and Mediterranean (cut off by the treaties ending the Crimean War), other powers were less biddable.

The red flag replaced the French tricolour and a civil war began between the Commune and the regular army, which attacked and recaptured Paris from 21–28 May in the Semaine Sanglante ("bloody week").

According to Karl Marx, the German Empire became "a military despotism cloaked in parliamentary forms with a feudal ingredient, influenced by the bourgeoisie, festooned with bureaucrats and guarded by police."

[146] The defeat in the Franco-Prussian War led to the birth of Revanchism (literally, "revenge-ism") in France, characterised by a deep sense of bitterness, hatred and demand for revenge against Germany.