A coup launched in Berlin by a group of radical socialist revolutionaries is brutally suppressed by right-wing paramilitary units from January 10 to January 15, 1919; the group's leaders, Karl Liebknecht and Rosa Luxemburg, are murdered.
Germany's long, ultimately losing struggle on the battlefield—culminating in the signing of the armistice in November 1918—and dismal conditions on the home front, including severe food shortages, caused many German socialists to turn away from the Social Democratic Party, which had supported the war effort in 1914 in the hopes that reform would follow a German victory. Although still the largest party in the Reichstag government, the Social Democrats saw their membership fall from over a million in 1914 to a quarter of that number in 1917.
By that time, a minority had broken off from the party and formed their own, the Independent Socialist Party. Luxemburg and Liebknecht led the Spartacists, the Marxist, revolutionary core group of the new party, which held firmly to the belief that German participation in a war was only justified in the case of a purely defensive conflict. In 1916, Luxemburg—under the nom de guerre Junius—had published a treatise in which she denied that the Great War was defensive for Germany, claiming instead that it was driven by imperialist, capitalist interests. Social democracy had failed the German working class, Luxemburg claimed, and the only solution was international class revolution, such as that envisioned by Vladimir Lenin and begun by the Bolsheviks in Russia in 1917.
On January 6, 1919, just weeks before the peace conference that would determine Germany's future opened in Paris, the Spartacists gathered in Berlin to begin a revolution. Luxemburg urged her followers not to attempt a coup before they mustered sufficient popular support, but she was unable to restrain them. The rebels launched their attacks on January 10. In the conflict that ensued, both Luxemburg and Liebknecht were captured and killed. Her body, thrown into a canal, was not retrieved until five months later.