Zagreb Resolution

During the World War I there were several initiatives regarding political consolidation of the South Slavs in different proposed forms. One involved introduction of trialism in Austria-Hungary whereby a consolidated polity encompassing the South Slavs would be established in addition to the existing Cisleithanian and Transleithanian parts introduced by the Austro-Hungarian Compromise of 1867. One such initiative was the May Declaration of the South Slavic members of the Imperial Council organised as the Yugoslav Club.^[2]

In 1918, the Yugoslav Club launched an initiative to improve collaboration among political parties representing the South Slavs in Austria-Hungary and endorsing the programme of unification of Croats, Slovenes, and Serbs. The initiative was described by the Yugoslav Club as "national concentration" for unification in a common state. However, they did not elaborate on the method or desired outcomes of such unification.^[3] As a part of the initiative, a conference was held in Zagreb attended by 43 opposition politicians from Croatia-Slavonia.^[4] The meeting was also attended by a group of politicians affiliated with the Zagreb-based Catholic daily Novine, members of the Social Democratic Party of Croatia and Slavonia, the Slovene People's Party, the National Progressive Party, as well as several politicians from Bosnia and Herzegovina, Dalmatia, Istria, and Međimurje. The Croatia-Slavonia's ruling Croat-Serb Coalition and opposition Croatian People's Peasant Party were invited, but did not attend except for a number of dissidents. The conference produced the Zagreb Resolution as a declaration on the need for political unification of the Croats, the Slovenes and the Serbs living in Austria-Hungary.^[5]

Niš Declaration

Following the outbreak of hostilities, Serbian leadership considered the war an opportunity for territorial expansion beyond the Serb-inhabited areas of the Balkans. A committee tasked with determining the country's war aims produced a programme to establish a Yugoslav state through the addition of Croatia-Slavonia, the Slovene Lands, Vojvodina, Bosnia and Herzegovina, and Dalmatia.^[6] This echoed Serbian Foreign Minister Ilija Garašanin's 1844 Načertanije – a treatise anticipating the collapse of the Ottoman Empire which called for the unification of all Serbs in a single state to pre-empt Russian or Austrian imperial expansion into the Balkans.^[7] However in its subsequent Niš Declaration, Serbian government declared its war aims, announcing the struggle to liberate and unify "unliberated brothers".^[8] The declaration spoke of "three tribes of one people" when referring to the Serbs, the Croats, and the Slovenes—applying the ideas of Yugoslavism.^[9] co

State of Slovenes, Croats and Serbs

The National Council of Slovenes, Croats and Serbs was established at the conclusion of a conference of political representatives of South Slavs living in Austria-Hungary held in Zagreb on 5–8 October 1918. Its establishment was devised as a means of fulfilment of the Zagreb Resolution on concentration of South Slavic political forces adopted in March of that year.^[10] The National Council declared its intention to work towards political independence and unity of the South Slavs. In the process of dissolution of Austria-Hungary, emperor Charles I announced his intention to embark upon a trialist reform of the empire on 16 October, but the National Council dismissed the announcement as belated. Instead, on 19 October, the National Council proclaimed itself the "central organ" of the new State of Slovenes, Croats and Serbs encompassing the Slovene lands, Croatia-Slavonia, Dalmatia, and Bosnia and Herzegovina.^[11]

On 29 October, the Croatian Sabor (nominally governing Croatia-Slavonia) declared severance of constitutional ties to Austria-Hungary and the Kingdom of Hungary and nullified the Croatian–Hungarian Settlement, declaring Croatia-Slavonia, together with Dalmatia and the city of Rijeka (previously organised as the Corpus separatum) a state independent of Austria and Hungary.^[12] Finally, the act of the Croatian Sabor recognised the National Council as the supreme authority in the State of Slovenes, Croats and Serbs.^[13]

Unification with Serbia

The National Council and its representatives took part in the process of political unification of South Slavs through establishment of the Kingdom of Serbs, Croats and Slovenes in late 1918. Due to lack of diplomatic experience, the council authorised the Yugoslav Committee, an ad-hoc group of politicians and activists, to speak on its behalf in international relations.^[14] After the Serbian government led by Nikola Pašić recognised the National Council as the legitimate representative of South Slavs living in the territory of Austria-Hungary,^[15] a National Council delegation, led by its president Anton Korošec, took part (jointly with the Yugoslav Committee and Serbian parliamentary opposition) in negotiations with Pašić, and signing of the Geneva Declaration on 9 November. The declaration was adopted as a means of speedy unification of the State of Slovenes, Croats and Serbs with the Serbia in a confederal state.^[16] Days later it was repudiated by Serbian government as well as the National Council's Croatian Serb vice-president Svetozar Pribičević who claimed the delegation was not authorised to conclude such an agreement.^[17]

Deterioration of security in the countryside and violence associated with the Green Cadres, as well as Italian Army advances following the collapse of Austria-Hungary and the Armistice of Villa Giusti, added urgency to the matter of unification. By 17 November, Italian forces captured Rijeka and were advancing through Carniola, reaching the vicinity of Ljubljana—with the aim of enforcing the Treaty of London which promised Italy territorial gains in return for participation in the war against Austria-Hungary. In response, the National Council appealed to Serbia seeking protection against Italy.^[18] On 24 November, the National Council designated a delegation to contact governments of Serbia and the Kingdom of Montenegro as well as other political parties in the two countries regarding unification in accordance with a set of conditions. The National Council defined the conditions as Instructions to its delegation. The envoys travelled to Serbia's capital, Belgrade on 1 December where they met with Prince Regent Alexander of Serbia. At the meeting, the delegation of the National Council ignored the Instructions and expressed their desire for unification stating no specific conditions. In response, Alexander granted their expressed wish and proclaimed unification of the Kingdom of Serbs, Croats and Slovenes that day.^[19]

On 3 December, the delegation of the National Council declared the core work of the council completed, although stating it would continue administrative tasks for a while. The council disbanded its non-central bodies,^[20] but continued its administative work in Zagreb until at least January 1919.^[21] The National Council decided to nominate all its members to the Temporary National Representation as the legislative body of the new state. However, the list of its representatives was drawn up by National Council member and new government minister Albert Kramer [sl] without input from relevant political parties, on authorisation by the regent.^[22]

Zagreb protest

Shortly after proclamation of the Kingdom of Serbs, Croats and Slovenes, there was a protest of soldiers in Zagreb suppressed by forces organised and led by the National Council.^[23] In the aftermath of the events the National Council disbanded the Zagreb-based 25th Regiment of the Royal Croatian Home Guard and the 53rd Regiment of the former Austro-Hungarian Common Army of the on the evening of 5 December.^[24] Furthermore, the council cited the clash and the Lipošćak affair as grounds to restrict the inclusion of Croatian officers who previously served in the Austro-Hungarian armed forces in army of the new unified state as unreliable.^[25]