Belgium and the Franco-Prussian War

Belgium and the Crisis of 1870

The Treaty of London in 1839 had recognized Belgium as a sovereign state but committed it to a policy of perpetual neutrality. Its independence was intended to be guaranteed by the Belgian Army and the military intervention of the Treaty's signatory powers. However, there were doubts that the Treaty would be honoured if Belgium was attacked especially in the aftermath of the Luxembourg Crisis of 1867.

The outbreak of the Franco-Prussian War led King Leopold II and the government of Jules d'Anethan, installed only two weeks before the war's outbreak, to fear that Belgium would be invaded. A career staff officer, Major General Guillaume, was appointed as a non-partisan expert Minister of War in the new cabinet. The gold reserves of the National Bank were hurried to the National Redoubt at Antwerp before the news became public. When this leaked out, it caused panic.

The Belgian Army was called up on the 15 July, the same day that both French and German armies mobilised. The Belgian troops were divided into two armies; the Army of Antwerp (15,000 men) was tasked with guarding the fortresses at Antwerp and across Belgium while the Army of Observation (55,000 men) was tasked with defending the national borders.

Many military leaders feared that, even after the outbreak of hostilities, as both French and Prussian armies manoeuvred on the Belgian border, one of them would seek a strategic advantage by an outflanking attack through Belgium, and most believed the army incapable of fending off any such attack. Indeed, in the early part of the war, French Marshal Canrobert brought an entire Army Corps (4 infantry divisions) to Châlons-sur-Marne in northern France as a reserve and to guard against any Prussian advance through Belgium. Despite key battles taking place very close to Belgian territory, including the Battle of Sedan just a few miles from the border, Belgium was never actually attacked.

In order to avoid giving the impression of belligerence in the conflict, Leopold requested that the French not commit Belgian members of the French Foreign Legion during the conflict. The French agreed and Belgian legionnaires remained in their base in French Algeria while their comrades were deployed to the front. The decision outraged the other legionaries and the Legion's march, Le Boudin, makes repeated reference to the fact that the Belgians "[only] shoot from their rear-end" ("tireurs au cul") because of it.