The Zimmerwald Conference was held in Zimmerwald, Switzerland, from September 5 to 8, 1915. It was the first of three international socialist conferences convened by anti-militarist socialist parties from countries that were originally neutral during World War I. The individuals and organizations participating in this and subsequent conferences held at Kienthal and Stockholm are known jointly as the Zimmerwald movement.

Pavel Borisovich Axelrod was an early Russian Marxist revolutionary. Along with Georgi Plekhanov, Vera Zasulich, and Leo Deutsch, he was one of the members of the first organization of Russian Marxists, Emancipation of Labor. After the 2nd Congress of the Russian Social Democratic Labour Party, he was part of the Menshevik faction, with which he was identified until his death.