Napoleon’s sudden appearance on the Danube was a shock to Austrian General Mack, who was dazzled into inactivity. In the “wheel” maneuver of October, Gunzburg, Elchingen and Ulm are all covered on one full-size map. Napoleon managed to seal off the Austrian army’s escape routes to the south and east, while Mack was fed erroneous news that revolution had broken out in France. The French captured Ulm, taking 42,000 troops at a cost of fewer than 10,000. In just 30 days they would race down the Danube and occupy Vienna.
Despite the loss of his capital, the Austrian Emperor Franz refused to surrender, retiring instead into Bohemia alongside the Russian Army under Kutuzov, meeting Tsar Alexander with a second army under Büxhowden at Olmütz.
By late November, the French were over-extended, without food and supplies. When the Austro-Russian army advanced en masse to the hills west of Austerlitz, Napoleon played along, ordering his troops to feign demoralization and a panicked retreat.