After 1918, the term Freikorps was used for the anti-communist paramilitary organizations that sprang up around the German Empire, including in the Baltic states, as soldiers returned in defeat from World War I. It was one of the many Weimar paramilitary groups active during that time.
In 1918 the Russian Bolsheviks ceded the Baltic areas to Germany under the Treaty of Brest-Litovsk. The Imperial German government established occupation governments in Estonia and Latvia and granted independence to a puppet government in Lithuania on March 25, 1918. The German Ober Ost occupation authorities under command of Prince Leopold of Bavaria favored the Baltic Germans, who had been the dominant social, economic, and political class in Courland, Livonia, and Estonia since the 13th century. On March 8 and April 12, 1918 the local Baltic German-dominated Land Council of Courland and the United Land Council of Livonia, Estonia, Riga and Ösel had declared themselves independent states, known as the Duchy of Courland and the Baltic State (Baltischer Staat), respectively. Both states proclaimed themselves to be in personal union with Prussia, although the German government never responded and acknowledged that claim.