When Hotze took up arms against the French in Switzerland, the revolutionary Swiss government in Bern revoked his Swiss citizenship. For the Coalition allies, though, his Swiss roots made him an ideal emissary between Vienna and Confederation sympathizers in Switzerland. He worked with William Wickham, and a Colonel Williams, an Englishman in Austrian service, to establish the Bodensee (Lake Constance) Flotilla. As Feldmarschall-leutnant, he commanded 15,000 troops in the Vorarlberg against France's Army of Switzerland, commanded by André Masséna. After fortifying Feldkirch, he overwhelmed the fortress at St. Luzisteig, an important pass (elevation: ) in the Canton of Graubünden that links Swiss Confederation and Liechtenstein. Then, realizing that the main French army had crossed the Rhine and moved north of Lake Constance, he reorganized the defenses of Feldkirch, and deputed command to Franjo Jelačić, an able officer and commander. Hotze took 10,000 of the 15,500 troops designated for the defense of the Vorarlberg toward Lake Constance, intending to support Archduke Charles' left wing at the battles of Ostrach and, a few days later Stockach. Although his forces did not arrive in time to participate in the battles, the threat of their pending arrival influenced French planning. In his absence, Jellacic's 5,500 men faced 12,000 under the command of generals of division Jean-Joseph Dessolles and Claude Lecourbe, inflicting enormous casualties (3000) on the French while suffering minimal losses (900) of their own.