Karl Paul August Friedrich Liebknecht (13 August 1871 – 15 January 1919) was a German socialist, originally in the Social Democratic Party of Germany (SPD) and later a co-founder with Rosa Luxemburg of the Spartacus League and the Communist Party of Germany. He participated in the Spartacist uprising of January 1919 that aimed to implement a Communist dictatorship.
Luxemburg and Liebknecht were captured in Berlin on January 15th by the Rifle Division of the Cavalry Guards of the Freikorps (Garde-Kavallerie-Schützendivision). Luxemburg was captured, interrogated, and shot. Her body was then flung into Berlin's Landwehr Canal. Liebknecht was shot in Berlin's Tiergarten and his body, without a name, deposited in a city morgue.
After their deaths, Liebknecht and Luxemburg became martyrs for Leftists. Despite the mass killings under Communist regimes an annual Liebknecht-Luxemburg Demonstration is held in Berlin, claimed to be the world's largest funerary parade and the biggest meeting of the German Left.
- Thadeusz, Frank (29 May 2009). "Revolutionary Find: Berlin Hospital May Have Found Rosa Luxemburg's Corpse". Der Spiegel. http://www.spiegel.de/international/germany/revolutionary-find-berlin-hospital-may-have-found-rosa-luxemburg-s-corpse-a-627626.html. Retrieved 30 November 2014.
- Wroe, David (18 December 2009). "Rosa Luxemburg Murder Case Reopened". The Daily Telegraph. https://www.telegraph.co.uk/news/worldnews/europe/germany/6840393/Rosa-Luxemburg-murder-case-reopened.html. Retrieved 30 November 2014.