The Spartacists were a threat from the left where from 5 – 12 January 1919, 50,000 members of the post-World War One CommunistParty, known as the Spartacists, rebelled in Berlin, led by Rosa Luxemburg and Karl Liebknecht.
The government was saved when, through the army, it armed bands of ex-soldiers, known as the Freikorps, who defeated the Spartacist rebels.
In the aftermath of the Spartacist uprising, communist workers' councils seized power all over Germany, and a Communist People's Government took power in Bavaria.
Liebknecht and Luxemburg were killed by the Freikorps after being arrested on the 15th.
By May 1919 the Freikorps had crushed all of the Spartacist uprisings.