Vladimir Lenin
The Zimmerwald Left was a revolutionary minority faction 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), Janis Berziņs (Latvia), Karl Radek (Poland), Julian Borchardt (Germany), Fritz Platten (Switzerland), Zeth Hoglund and Ture Nerman (Sweden). It was the first step towards forming what later became the Comintern.
Credit: https://en.wikipedia.org/wiki/Zimmerwald_Left