Social Democratic Union 'Proletarian'

Social Democratic Union 'Proletarian' was a political party organization in Bulgaria 1906-1908. The organization was led by Dimitar Blagoev, who had been expelled from the Narrow Socialists for being an 'anarcho-liberal. 'Proletarian' merged with the Broad Socialists, and would represent the leftwing tendency within that movement from 1909 onwards[1]

References

1. Linden, Marcel van der, and Jürgen Rojahn. The Formation of Labour Movements, 1870-1914: An International Perspective. Contributions to the history of labour and society, v. 2. Leiden: E.J. Brill, 1990. p. 406