The Slovene People's Party launched a movement for self-determination, demanding the creation of a semi-independent South Slavic state under Habsburg rule. The proposal was picked up by most Slovene parties, and a mass mobilization of Slovene civil society, known as the Declaration Movement, followed. This demand was rejected by the Austrian political elites; but following the dissolution of the Austro-Hungarian Empire in the aftermath of the First World War, the National Council of Slovenes, Croats and Serbs took power in Zagreb on 6 October 1918. On 29 October, independence was declared by a national gathering in Ljubljana, and by the Croatian parliament, declaring the establishment of the new State of Slovenes, Croats, and Serbs.