Rubuta ci gaba ga wannan sakin layi - A lokacin da juyin juya halin Faransa ya fara, Tharreau ya amince da juyin juya halin juyin juya hali. A cikin 1792, ya shiga cikin masu sa kai na Maine-et-Loire kuma daga baya a wannan shekarar ya zama babban jami'in soja na 2 na masu sa kai na Mayence. A shekara ta 1794, a lokacin da Faransanci ta tsoratar da shi, ya kasance Janar Janar a cikin Sojojin Ardennes. A shekara ta 1799, Jean Victor Tharreau ya kasance kwamandan brigade a cikin sojojin Faransa na Danube, kuma ya yi yaƙi a yakin Ostrach
da kuma Stockach na farko. A ranar 20 ga Afrilu, an daukaka shi zuwa Janar na Division. André Masséna ya sanya shi kwamandan layin gaba, don kare birnin Zurich na Switzerland, a cikin 1799; rashin biyayya na Jean-de-Dieu Soult a yakin Winterthur a watan Mayu 1799 ya ba da gudummawa ga rashin iyawar Tharreau don riƙe layin gaba, wanda ya tilasta wa Faransa komawa baya a Zurich da kuma nasarar da Faransa ta yi a yakin farko na Zurich a ranar 4 zuwa 7 ga Yuni.