League of the Just
In 1836, Fein was expelled from Switzerland and went to Paris, where he joined the utopian communist 'League of the Banned', founded by Wilhelm Weitling. On its behalf, Fein published the journal "Der Geächtete" ("The Banned"). The League was subsequently renamed 'League of the Just' and later, under the influence of Karl Marx, the 'Communist League'. In France, Fein also befriended the exiled poets Heinrich Heine and Georg Büchner. In 1837, Fein was arrested and expelled from France.