Literally translated from the German, the word means ‘Free Corps’, though this term does not really express the intention behind the nomenklature. Freikorps were para-military formations formed throughout Germany after the end of the World War. These bodies were led by former officers and non-commissioned officers who had had difficulty adjusting to civilian life after four years of mainly trench warfare. The men tended to be nationalist and unemployed.
The Free Corps were used by the Allies, in a supremely cynical act, to fight against Bolsheviks in Lithuania and Latvia; also to smash left-wing rebellions at home. The Freikorps it was who murdered left-wing leaders such as Karl Liebknecht and Rosa Luxembourg.
In true political style, they were also used to support right-wing coups, such as the Kapp Putsch (q.v.) in 1920. But they were disbanded in 1921, officially, though many groups continued to act as murder squads, assassinating politicians from the WeimarRepublic (q.v.). They took the trouble to accuse their victims first of betraying the German people. Among their targets were Matthias Ertzberger and Walther Rathenau.
The Freikorps were popular in Germany though, and in each case the German courts imposed mild sentences on those responsible for political murders. Many members joined up with the SA in the Thirties, in order to continue their murderous activities. Nazi leaders knew, as was demonstrated at the Nuremburg Trials (q.v.) where the SA and later the SS were recruiting their teams from (see Kristalnacht on this website).