The fall of Strasbourg on 28 September 1870 allowed Preventing_or_letting the German army under August von Werder to move Motion south against Belfort .

Werder 's forces reached Arriving Belfort and invested Besieging the city on 3 November .

On 15 January 1871 Bourbaki attacked Attack Werder along the Lisaine River ; however after a three-day battle he was repelled Defending and his army retreated Escaping into Switzerland .

After the German victory at Wörth , troops from the Grand Duchy of Baden under Prussian General August von Werder were detached to capture Arrest Strasbourg with the help Assistance of two Prussian `` Landwehr '' divisions which had been guarding Defending the North Sea coast .

A shell shortage forced Motion Werder to lower Cause_change_of_position_on_a_scale the intensity of the German fire on 26 August and switch Change to formal siege Besieging operations .