Herzegovina's workers managed to establish their first organisations in 1903, in the form of mutual aid societies. The workers' demands for higher wages and better working conditions, and for the general improvement of their economic and social position, were much intensified during the spring and summer of 1905. Sokolović returned to Sarajevo during that period and, on 22 May, became an employee of the National Printing House (founded in 1866 as Sopron's Printing House). At that time in Bosnia and Herzegovina, there were only isolated groups of workers who made efforts to improve their position, and they had vague and conflicting ideas of how to organise themselves. Sokolović began agitating in the printing house, and six weeks after he was employed there, its workers went on strike. For this success, Sokolović received a sentence of four days' imprisonment and the dismissal from his job. He then fully devoted himself to organising the labour movement in Sarajevo. On his initiative, representatives of workers of various trades gathered on 10 August 1905. They delivered a resolution, composed by Sokolović, requesting the city authorities to grant the workers the right of free association and of holding public meetings. After no response came from the authorities, Sokolović gathered the workers' representatives again on 21 August. They made a formal request to hold an assembly six days later to establish their organisation, and this request was soon granted. The first public assembly of workers in Bosnia and Herzegovina was held as planned, on 27 August 1905; it had around 350 participants. The provincial government sent an envoy to be present at this gathering. It was presided by Alojz Supančič (a textile worker, originally from Slovenia), and its minutes were recorded by Sokolović and Mustafa Handžić (a shoemaker). The assembly accepted the proposition to found the General Workers' Union (Glavni radnički savez), the main goal of which was "to work on the intellectual, moral and material advancement of workers, to awaken their class consciousness, and to spread solidarity among them". The Rules of the General Workers' Union (Pravila Glavnog radničkog saveza), whose articles were composed by Sokolović, was also unanimously accepted. The assembly elected a provisional management of the organisation, with Ilija Kamber (a construction worker) as its president and Sokolović as its secretary. It was the first trade union to be founded in Bosnia and Herzegovina. Beside this general union, during September 1905 similar assemblies