Riesch occupied the villages of Ober- and Unter-Elchingen on the north bank of the Danube River. At the Battle of Elchingen on 14 October 1805, Marshal Ney's superior force attacked Riesch's 9,000 soldiers, drove them off the heights, and forced them back into Ulm. During the battle, Riesch commanded two brigades under Daniel Mécsery and Johann Laudon, with 14 infantry battalions, 11 cavalry squadrons, and 12 artillery pieces. The main French attack came from the south, as Louis Henri Loison's division crossed a partly destroyed bridge over the river and went on to storm the Elchingen Abbey. Riesch fought back until a second French division approached from the east, when he ordered a retreat. Under pressure of cavalry attacks, Austrian morale collapsed and Riesch's command suffered very heavy losses. A few days later, Mack surrendered with 27,000 men, including Riesch, at the Battle of Ulm.