Ka kammala wannan jumla: A lokacin da juyin juya halin Faransa ya barke a shekara ta 1789, Gazan ya koma Grasse kuma ya shiga National Guard. A shekara ta 1790, ya zama kyaftin kuma, a shekara ta 1791, ya zama laftanan-kolonel na rukunin masu sa kai na yankin Var. A shekara ta 1792, tare da sanarwar
a lokacin yakin da Austria, an tura shi zuwa 27th Regiment. Da farko rundunarsa ta yi aiki a Strasbourg, amma a watan Disamba na 1793, ya shiga cikin yakin Wissembourg. A watan Mayu na 1794, Gazan ya zama kwamandan kwamandan na sabon 54th Demi-Brigade. A ranar 4 ga Yuli, ya kori Prussians a Kuppenheim ta hanyar ba da umarnin drummers ya doke wani cajin, ya tabbatar da Prussians cewa sun kasance mafi yawa. An ba shi mukamin kanar birgedi a ranar 11 ga Yuli kuma ya jagoranci sojojinsa zuwa nasara a kan Prussians a Trippstadt.