Kammala jumla mai zuwa: Josias ya shiga rundunar sojan Habsburg a matsayin Kanal a 1759, ya shiga cikin Yakin Shekaru Bakwai, kuma ya kai matsayin Laftanar Field Marshal a 1773. A cikin yaƙin Rasha-Turkiya-Austria na 1788, ya umurci rundunar soja a ƙarƙashin Freiherr von Laudon, ya mamaye Moldavia, ya kama Khotyn a Bessarabia kuma ya shiga cikin nasarar Aleksandr Suvorov a yakin Focșani (1 Agusta 1789). Bayan ya doke babban rundunar sojojin Ottoman a karkashin Grand Vizier Koca Yusuf Pasha a cikin
Yaƙin Rymnik, ya kama mafi yawan yankin Wallachia, gami da Bucharest, wanda jama'a suka yi maraba da shi bayan tseren Yarima Nicholas Mavrogenes ("duba Tarihin Bucharest"), kuma ba da daɗewa ba bayan ya zama marshal.