Rosa Luxemburg (1870 - 1919) was a socialist politician, an advocate of social revolution and head of the Spartakusbund (together with Karl Liebknecht). She wrote "die Akkumulation des Kapitals" (1913) and "Das Kommunistische Manifest" in 1918. She was arrested and murdered by Freikorpstroups in Berlin in 1919.
Ernst Thaelmann (1886 - 1944) was a member of the German communist party (KPD) since 1920. He occupied increasingly important political positions with the party, from parliamentary representative to head of the KPD in the Weimar Republic. He also was a candidate for president. In 1933, he was arrested by the Nazis. He died at Buchenwald concentration camp in 1944.