Rubuta ci gaba don wannan sakin layi - Dan uwan sarki Stanislaus Augustus na Poland (), Poniatowski ya fara aikin soja a 1780 a cikin sojojin Austriya, inda ya sami mukamin kanal. A shekara ta 1789, bayan ya bar aikin Austriya, ya shiga rundunar sojojin Poland bisa bukatar kawunsa. Poniatowski, yanzu yana da mukamin babban janar kuma kwamandan Sojojin Sarauta, ya shiga cikin Yakin Poland-Rasha na 1792
, yana jagorantar sojojin kambi a nasarar yakin Zieleńce. Bayan goyon bayan sarki ga Targowica Confederation na 1792, Poniatowski ya ji tilasta yin murabus. A shekara ta 1794 ya shiga cikin Tashin Kościuszko kuma ya dauki nauyin kare Warsaw - wanda hukumomin Rasha suka yi watsi da shi har zuwa 1798.