Rubuta ci gaba don wannan sakin layi - Pérusse des Cars ya yi aiki a cikin Sojojin ruwan Faransa kafin ya shiga Sojojin kuma an nada shi Maître de camp (daidai da Kanal) na rundunar Dragoons-Artois a 1774. Bayan mutuwar ɗan'uwansa na biyu a lokacin yakin Saintes
a cikin 1782, ya ɗauki taken Baron des Cars. A cikin 1783, ya zama Maître d'hôtel du Roi na farko na Sarki. A watan Janairun 1784, an sanya shi Brigadier na sojan doki wanda aka bi ta Lt.-Gen. a ranar 9 ga Maris 1788. Ya yi aiki a matsayin député aux États-généraux a 1789, kuma ya bar ƙasar tare da sarakunan Faransa a 1790 a lokacin juyin juya halin Faransa. A shekara ta 1791, an tura shi aikin diflomasiyya zuwa Sarki Gustav III na Sweden, sannan kuma wasu ayyukan, ciki har da Berlin.