The Zimmerwald Left was a revolutionary minority fraction at the Zimmerwald Peace Conference of 1915, headed by Lenin. The Left of the Zimmerwald Congress was made up of eight out of 38 people: Lenin, Zinoviev (Russia), Jānis K. Bērziņš (Latvia), Karl Radek (Poland), Julian Borchardt (Germany), Fritz Platten (Switzerland), Zeth Höglund and Ture Nerman (Sweden). It was the first step towards forming what later became the Communist International.
- R. Craig Nation, War on War: Lenin, the Zimmerwald Left, and the Origins of Communist Internationalism. (1989) Chicago: Haymarket Books, 2009.