[1] Mihailo Mihaljević graduated from cadet school, and then served in a Petrovaradin regiment which was part of the Habsburg Military Frontier.
He was a Slavonian general command for several years with the rank of major and later colonel in the Imperial Austrian Army.
[2][3][4][5] In the operations of the Austrian army in 1789, with the frigate Stanko, he ensured the attack on Belgrade via the Danube river, and then took part in the occupation of Paraćin, Jagodina, Ćuprija, Karanovac, Kruševac and Aleksinac, all in modern Serbia.
[8] Koča's militia quickly took over Palanka and Batočina, attacked Kragujevac, and reached the Constantinople road, cutting off the Ottoman army from the Sanjak of Niš and Sanjak of Vidin.
In 1792, Colonel Mihaljević went on to organize the Serbian and Slavonian Freikorps with which he participated in the French Revolutionary Wars; while serving in that campaign, he was killed on 26 April 1794.