When the Franco-Prussian War broke out in 1870, Uhrich was recalled to active service. He replaced "Général de division" Auguste-Alexandre Ducrot as commanding officer of the 6th Military Division and at his own request became military governor of Strasbourg. Immediately after their victory in the Battle of Wörth (also known as he Battle of Reichshoffen and the Battle of Frœschwiller) on 6 August 1870, forces of the German states began to arrive at Strasbourg and initiated a siege of the city on 13 August with a force that soon reached a strength of 40,000. The German forces — consisting of elements of the Prussian Army and of the army of the Grand Duchy of Baden — began a desultory artillery bombardment of the city and its fortifications — designed by Sébastien Le Prestre de Vauban during the seventeenth century and obsolete by 1870 — on 14 August while the German commander, Prussian "Generalmajor" August von Werder, considered ways to bring the siege to a quick end. Werder informed Uhrich that his forces would begin an intensive bombardment of the city if it did not surrender, and, after Uhrich refused, the bombardment began on 23 August.