By summer 1805, a new coalition against Napoleon’s Imperial France had formed, beginning the War of the Third Coalition. In September, Austrian General Mack began a march into Bavaria to secure the city of Ulm which had a favourable defensive position that he believed would be necessary to protect against the inevitable French invasion. Napoleon moved his army through Prussian Ansbach where they formed a line north of Mack’s position. At first Napoleon was unsure of Mack’s location but he gradually deduced a picture of the situation, whilst Mack was unaware of the impeding danger until it was too late. The French encircled Mack’s forces, blocking Russian assistance from the east, and Mack surrendered along with 25,000 troops on 20 October. Archdukes John and Charles retreated out of Italy and the French army seized Vienna on 13 November whilst pursuing Kutuzov on his retreat east to meet with the rest of the Austrian forces.
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