Alexander Parvus

Alexander Israel Helphand (born Israel Lazarevich Gelfand, Russian: Израиль Лазаревич Гельфанд; 27 August 1867 – 12 December 1924), better known as Alexander Parvus, was a Russian-born Marxist theorist, journalist, and activist who became a prominent figure in the Social Democratic Party of Germany (SPD).

Parvus is best known for his collaboration with Leon Trotsky in developing the theory of permanent revolution around 1905, and for his controversial role during World War I. He devised a plan to destabilize the Russian Empire by promoting internal revolution, which he presented to the German government. With German financial support, he established a network to aid the Bolsheviks and is widely remembered for his part in arranging Vladimir Lenin's return to Russia from exile in the "sealed train" in 1917.

After the Bolsheviks came to power, Lenin rejected Parvus's request to return to Russia, stating that "the cause of the revolution should not be touched by dirty hands". Parvus remained in Germany, becoming a wealthy industrialist and a political advisor to leaders of the Weimar Republic. His life was marked by sharp contrasts between his revolutionary activities, his intellectual contributions to Marxism, and his later affluence and political maneuvering, which made him an enigmatic and highly controversial figure.