French forces under marshals Joachim Murat and Nicolas Soult beat an Austrian army corps under Kienmayer on 7 October at Donauwörth and crossed the Danube.

After Austrian forces under general Karl Mack entered Bavaria, the French army left the camp de Boulogne and reached the Rhine at the end of September 1805.

The Austrian general based his army around the Bavarian town of Ulm beside the Danube, ready to meet the French force when it exited the Black Forest.

The battle pitted Soult's corps (mainly Dominique-Joseph René Vandamme's division[1]) and Murat's cavalry[2] against the Austrian force.

The French victory enabled an initial crossing of the Danube and allowed the Grande Armée to deploy on the river's right bank as well as continuing its enveloping manoeuvre.