The Ulm Campaign of October 1805 resulted in an Austrian disaster when the Grande Armée of Napoleon enveloped and destroyed most of its units. Afterward, only Michael von Kienmayer's fleeing corps and a newly-arriving Russian army under Mikhail Kutuzov stood between Napoleon and the Austrian capital of Vienna. After hearing the news of Ulm, the main army of Archduke Charles, Duke of Teschen began withdrawing from northern Italy and Archduke John of Austria's smaller army pulled out of the County of Tyrol. In the confusion, Rohan's brigade became separated from John's army. First, Rohan attempted to join part of Charles' army. Failing, he had his men move south to link up with the Austrian garrison of Venice. After an epic march Rohan's brigade was cornered short of Venice. The issue of the