[1] In July 1891, on the initiative of Dimitar Blagoev, the social democratic circles of Tarnovo, Gabrovo, Sliven, Stara Zagora, Kazanlak and other cities united to form the Bulgarian Socialdemocratic Party.
In 1892 this group, led by Yanko Sakazov, founded a reformist organization, the Bulgarian Social Democratic Union (hence their name, Unionists).
In 1894, Blagoev’s supporters agreed to unite with the Unionists in the interests of working-class unity and took the name Bulgarian Social Democratic Workers' Party.
Congress changed the statutes and decided to publish the newspaper Rabotničeski vestnik for agitation and propaganda among the workers.
In 1900, in the context of extensive peasant unrest in Bulgaria, the reformist elements grouped themselves around the magazine Obšto delo, edited by Sakyzov, which propagandized the idea of class cooperation.