The Battle of Elchingen, fought on 14 October 1805, saw French forces under Michel Ney rout an Austrian corps led by Johann Sigismund Riesch. This defeat led to a large part of the Austrian army being invested in the fortress of Ulm by the army of Emperor Napoleon I of France while other formations fled to the east. Soon afterward, the Austrians trapped in Ulm surrendered and the French mopped up most of the remaining Austrians forces, bringing the Ulm Campaign to a close.