Augereau commanded a camp in Brest, Brittany, during preparations for the invasion of Britain. When Napoleon called off the invasion because of the growing threat from Austria and Russia, the camp became the VII Corps of the "Grande Armée". With this force, Augereau fought in the War of the Third Coalition. His corps was charged with protecting the army's lines of communications during the Ulm campaign. He fought in the battles of Konstanz and Bregenz, before tracking down and destroying General Franz Jellacic's Austrian division at Dornbirn in Vorarlberg on 13 November 1805. This was followed by the occupation of Frankfurt am Main. His wife Gabrielle died while he was away.