Activities of the pro-Yugoslav forces in the Transleithanian Kingdom of Croatia-Slavonia on 30 May 1917 resulted in adoption of the May Declaration by the Yugoslav Club, a group of Croatian and Slovene deputies in the Reichsrat (the legislature of Cisleithania in Vienna). The Declaration sought the unification of all the lands in the Habsburg monarchy populated by Slovenes, Croats, and Serbs in one independent entity.
