After the end of World War I, Dirlewanger, described in a police report as "a mentally unstable, violent fanatic and alcoholic, who had the habit of erupting into violence under the influence of drugs," joined various Freikorps right-wing paramilitary militias and fought against German communists in Ruhr and Saxony, and against Polish nationalists in Upper Silesia. He participated in the suppression of the German Revolution of 1918–19 with the Freikorps in multiple German cities in 1920 and 1921. Later, he commanded an armed formation of students which was set up by him under the Württemberg "Highway Watch".