Rosa Luxemburg and Karl Liebknecht were prominent German communists who were assassinated on this day in 1919 by the German Freikorps, a group of government-sponsored paramilitary forces, after the Spartacist Uprising.

Luxemburg and Liebknecht had co-founded the Spartacist League and the Communist Party of Germany (KPD), groups that had been engaging in revolutionary political activity.

In 1919, Luxemburg and Liebknecht participated in the "Spartacist Uprising", an armed rebellion against the German state. The uprising was forcibly put down by the Freikorps and, for their role in it, both Luxemburg and Liebknecht were tortured and summarily executed by the government forces on this day that year.

Karl Liebknecht and Rosa Luxemburg have since become celebrated martyrs of the German left. Since 1919, an annual Liebknecht-Luxemburg Demonstration has been held in Berlin, the world's largest funerary parade and the biggest meeting of the German left. The annual "L-L Demo" is held on the second Sunday in January. In 2016, 14,000 people attended the rally in Liebknecht's and Luxemburg's honor.

Epitaphs composed by German playwright Bertolt Brecht read as follows:

Epitaph for Karl Liebknecht Here lies Karl Liebknecht The fighter against war When he was struck down Our city still continued to stand.

Epitaph for Rosa Luxemburg Here lies buried Rosa Luxemburg A Jewess from Poland Champion of the German workers Murdered on the orders of The German oppressors. Oppressed; Bury your differences!

"Marxism is a revolutionary worldview that must always struggle for new revelations. Marxism must abhor nothing so much as the possibility that it becomes congealed in its current form. It is at its best when butting heads in self-criticism, and in historical thunder and lightning, it retains its strength."

- Rosa Luxemburg