Paramilitary groups were formed throughout the Weimar Republic in the wake of Germany's defeat in World War I and the ensuing German Revolution. Some were created by political parties to help in recruiting, discipline and in preparation for seizing power. Some were created before World War I. Others were formed by individuals after the war and were called "Freikorps" (Free corps). The party affiliated groups and others were all outside government control, but the Freikorps units were under government control, supply and pay (usually through army sources).
After World War I, the German Army was restricted to 100,000 men, so there were a great number of Imperial German Army soldiers suddenly de-mobilized. Many of these men were hardened into a Frontgemeinschaft, a front-line community. It was a spirit of camaraderie that was formed due to the length and horrors of trench warfare of World War I. These paramilitary groups filled a need for many of these soldiers who suddenly lost their "family"—the army. Many of those soldiers were filled with angst, anger and frustration over the loss and horror of the war.
Paramilitary groups were quite active in the ill-fated Republic, sometimes used to seize power and other times to quell disturbances. Freikorps were used in the Baltic region in 1919 by General Rüdiger von der Goltz to protect German interests against Russia. Other Freikorps members engaged in sabotage acts against French and Belgian occupying forces in the Ruhr in 1923 by blowing up bridges. Yet other Freikorps orchestrated the Kapp Putsch and the Beer Hall Putsch. The Communists used their groups to seize power in several places in the Weimar Republic at different times, forming Räterepubliken. Other paramilitary groups were used to quell these uprisings. Freikorps events are displayed in the Weimar Timeline.