Clara Josephine Zetkin née Eißner (5 July 1857 – 20 June 1933) was a German Marxist theorist, activist, politician and advocate for women's rights. Until 1917, she was active in the Social Democratic Party of Germany, then she joined the Independent Social Democratic Party of Germany (USPD) and its far-left wing, the Spartacist League; this later became the Communist Party of Germany (KPD), which she represented in the Reichstag during the Weimar Republic from 1920 to 1933.