Andreu Nin

A teacher and journalist, during his youth he was involved in various political movements until he joined the anarchist Confederación Nacional del Trabajo (CNT). During his stay in Russia, he witnessed the Russian Revolution, which marked his conversion to Marxism. After his return to Spain, he later became one of the founders of the small but active Workers' Party of Marxist Unification (POUM). He eventually became a leading figure in Spanish revolutionary Marxism. He disappeared during the course of the Spanish Civil War, having been arrested by the Republican authorities following the "May Days". Provided by Wikipedia