Born in Kamnik, Maister was educated at military schools of the then Austria-Hungary. At the end of WWI he held the rank of major. On October 30th 1918 the Maribor city council (made up of mostly of Germans) declared Maribor and its surrounding area part of the then Republic of German-Austria. On November 1st Maister made a speech in one of the barracks of Maribor wherein he strongly opposed the above mentioned declaration and insisted Maribor become part of the State of Slovenes, Croats and Serbs (which later became part of Yugoslavia). With the help of Slovenian soldiers he took military control of the city. The city’s administration was then taken over by the so called National council which gave Maister the rank of General. The surprised German side quickly recovered and managed to secure the fouding of the so called Green guard (Schutzwehr). After that Maister started mobilizing Slovenian soldiers. These soldiers who fought under Maister's command in northern Slovenia became known as Maister's fighters (Maistrovi borci). After gathering about 4000 men Maister forced the Schutzwehr to surrender. From that point on Maribor was firmly in Yugoslav hands. Later Maister fought against Austrian forces in other parts of what today is northern Slovenia. Today one of Maribor’s central squares is named him.