Kammala jumla mai zuwa: An haife shi a ranar 20 ga Oktoba 1760 a Lorry-Devant-le-Pont, a Masarautar Faransa, Roget ya shiga aikin soja a cikin rukunin 7 na "chasseurs a cheval" (sojan doki mai sauƙi), a ranar 13 ga Mayu 1777, a matsayin soja mai sauƙi. A shekara ta 1793, a matsayin "sabon-laftanal" ya yi aiki a rundunar Custine a Siege na Mainz. Daga baya ya yi aiki tare da Marceau-Desgraviers da Kleber don murkushe tawayen Vendee. A ƙarshen tayar da hankali a cikin Vendee, ya kai matsayin mai ba da shawara ga janar. An sake kiran shi zuwa rundunar sojojin Rhine da Moselle, Janar Desaix ya ba shi umurnin 13th Dragoon Regiment, wanda ya sami nasarar yaƙi a
Valmy shekaru hudu da suka gabata; a yakin Dierstein, ya jagoranci 13th a cikin caji kuma ya ci Austrian "Regiment D'Alton", yana ɗaukar tutoci biyu da bindigogi biyar. Daga nan sai ya juya zuwa Offenburg, inda ya kori Austrians kuma ya bi su bayan Gengenbach; a cikin mataki na biyu, ya ɗauki bindigogi hudu daga Austrians, da akwatuna arba'in na bindigogi, da kuma yawan fursunoni.