The Siege of Belfort (3 November 1870 - 18 February 1871) was a 103-day military assault and blockade of the city of Belfort, France by Prussian forces during the Franco-Prussian War. The French garrison held out until the January 1871 armistice between France and the German Empire obligated French forces to abandon the stronghold in February 1871. During the 83 days of the heart of the siege the German army fired more than 400.000 shell on the town, or approximatively 5,000 per day.