Key Facts
- Duration
- 103 days (3 Nov 1870 – 18 Feb 1871)
- Siege begun
- 3 November 1870
- Garrison surrender date
- 18 February 1871
- Key relief battle
- Battle of the Lisaine, 15–17 January 1871
- Commemorative monument
- Lion of Belfort, inaugurated 1880
Strategic Narrative Overview
Werder's forces invested Belfort on 3 November 1870, but French resistance prevented a complete encirclement. General Bourbaki assembled a relief army and attacked Werder along the Lisaine River on 15 January 1871; after three days of fighting, Bourbaki was repulsed and his army eventually driven into Switzerland. A German assault on 27 January 1871 under General von Tresckow was also repulsed, and siege operations continued until an armistice was reached.
01 / The Origins
Belfort occupied a strategic gap between the Vosges and the Jura Massif, forming the gateway between Alsace and central France. Following the rout of the French Army of the Rhine in northern Alsace and the fall of Strasbourg on 28 September 1870, Prussian General August von Werder's forces were freed to advance south. Commander Pierre Philippe Denfert-Rochereau hastily expanded Vauban's original fortifications to prepare for the approaching German siege.
03 / The Outcome
An armistice between France and Germany was signed on 15 February 1871. President Thiers ordered Denfert-Rochereau to surrender; on 18 February the garrison marched out with full honours of war, retaining their weapons and baggage. Under the Treaty of Frankfurt, Belfort and its surrounding area were uniquely spared from annexation by Germany, unlike the rest of Alsace.
Belligerents & Mobilization Analysis
Side A
1 belligerent
August von Werder, General von Tresckow.
Side B
1 belligerent
Pierre Philippe Denfert-Rochereau, Charles Denis Bourbaki.
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.