The annexation of Vojvodina to the Kingdom of Serbia was carried out in November 1918, at the end of First World War, in the context of the creation of Yugoslavia. The ethnically mixed region consisting of parts of Bačka, Banat and Baranya, collectively referred to as Vojvodina by the Serbs, had previously been a part of Austria-Hungary. Parts of the territory were promised by the Allies of the First World War to Serbia and Romania in return for participation in the war. At the same time, the National Council of Slovenes, Croats and Serbs based in Zagreb declared an independent state of the South Slavs living in Austria-Hungary at the time, with the intention of forming a wider South Slavic state with Serbia. The Serbian National Committee was convened in Subotica to prepare for the inclusion of Vojvodina into the future wider South Slavic state.
The Royal Serbian Army started to replace the Austro-Hungarian forces in the region following the Armistice of Villa Giusti. The boundaries of Serbian military occupation were determined by mid-November through the Armistice of Belgrade. As the Serbian army approached Novi Sad, the Serbian National Committee debated whether to join the unified state through annexation to Serbia or through representation in the Zagreb-based National Council and the State of Slovenes, Croats and Serbs. The body opted for the latter solution, but its decisions were annulled by the newly-established Serbian military administration.
Regent Alexander, supported by the army and Croatian Serb leader and National Council deputy president Svetozar Pribićević, decided to have Vojvodina annexed to Serbia before any unification. The move was meant to undermine the National Council in Zagreb and rescind acceptance of the recently adopted Geneva Declaration. The document was negotiated between the Serbian Prime Minister Nikola Pašić and the National Council to determine the constitutional framework of the South Slavic unified state. The declaration was accepted by Pašić under international pressure, but the document did not satisfy the interests of Regent Alexander.
After repudiation of the Geneva Declaration, the Great People's Assembly of Serbs, Bunjevci and other Slavs in Banat, Bačka and Baranja was convened in Novi Sad as a popular assembly to give the annexation the guise of self-determination and legitimacy. The delegates largely consisted of representatives of various Slavic ethnic groups of Vojvodina – amounting to 38% of the total population at the time. Non-Slavs, deemed enemy nations, received only token representation. The method of annexation of Vojvodina and the treatment of the National Council caused resentment, especially by the Hungarians towards the Allies and the Croats against the Croatian Serbs. Historian Charles Ingrao and philosopher and legal scholar argue that the episode helped shape Alexander's later authoritarian approach to governing the Kingdom of Serbs, Croats and Slovenes (later renamed Yugoslavia).
Background
Over the course of First World War, prewar ideas regarding political consolidation of parts of Austria-Hungary inhabited by the South Slavs were developed under the influence of wartime events. Initially, such designs involved proposals to revise the Compromise of 1867 and introduce trialism in Austria-Hungary. Those efforts culminated with the unsuccessful 1917 May Declaration championed by Anton Korošec.
In late 1914, while defending against the Austro-Hungarian invasion, the government of the Kingdom of Serbia announced its objectives in the Niš Declaration, calling for the liberation of "unliberated brothers", referring to the South Slavic population of Austria-Hungary. In 1915, the Triple Entente sought to entice the Kingdom of Italy to join the war as an Allied Power by offering it various territories, including portions of Austro-Hungarian eastern Adriatic Sea coast such as Dalmatia and Julian March (including Istria), under the Treaty of London. At roughly the same time, the Triple Entente offered Serbia Bačka, Bosnia, Herzegovina, Syrmia, and Slavonia as compensation for territories expected to be offered to Bulgaria in order to obtain alliance with that country. The region of Banat was promised to the Kingdom of Romania in 1916, but separate Romanian peace with the Central Powers voided the promise.
A group of Dalmatian politicians led by Frano Supilo and Ante Trumbić set up the Yugoslav Committee with the aim of promoting the detachment of lands inhabited by the South Slavs from Austria-Hungary. Following unsuccessful attempts by Serbia to influence the Triple Entente to apply the principle of self-determination to the South Slavic lands, the Yugoslav Committee endorsed the idea of a political union of the Austro-Hungarian South Slav-inhabited lands and Serbia and the creation of Yugoslavia. The Yugoslav Committee saw the unification as a matter of necessity required to prevent partitioning of Croatia between Italy, Serbia, and Hungary. In 1917, representatives of the Yugoslav Committee and the government of Serbia issued the Corfu Declaration of their intent to achieve the union.
In the final days of the war, as the dissolution of Austria-Hungary was unfolding, the National Council of Slovenes, Croats and Serbs, chaired by Korošec, was established as the governing body of the South Slavs living in Austria-Hungary and the short-lived State of Slovenes, Croats and Serbs after the empire's breakup. All South-Slavic inhabited lands of the former Austria-Hungary were represented in the National Council, except Bačka and Banat – which were allocated seats in the council, but the seats were largely left vacant.
Ethnic background
The territories of historical regions of Banat, Bačka, and Baranya largely corresponded to five counties of the former Kingdom of Hungary. According to the 1910 census, the territory was multi-ethnic with substantial Hungarian, German (Danube Swabian), Romanian, and Serbian communities. Bačka largely corresponded with the Bács-Bodrog County, with a population of 812,385 of which 45% were Hungarians, 24% Germans and 18% Serbs. Banat largely corresponded with the Temes, Torontál, and Krassó-Szörény counties: Temes County had a population of 500,835, of which 34% were Romanians, 33% Germans, 16% Hungarians and 14% Serbs; Torontál County had a population of 615,151, of which 33% were Serbs, 30% Germans, 21% Hungarians, and 14% Romanians; and Krassó-Szörény County had a population of 466,147 of which 72% were Romanians, 12% were Germans, 7% were Hungarians, and 3% were Serbs. Baranya County had 352,478 inhabitants and a Hungarian majority (57%); the most numerous minority were Germans (32%), followed by Serbs (4%) and Croats (3%). The five counties had the combined population of 2.75 million. The plurality was Hungarian (29%) and the second-largest group were Germans (25%), followed by Romanians (22%). Serbs comprised 16%.
According to the 1910 census, Serbs and Croats accounted for one third of the population inhabiting the portion of the five former counties' territory that would ultimately be assigned to the postwar Kingdom of Serbs, Croats and Slovenes as defined by the Paris Peace Conference. All Slavic ethnic groups combined amounted to 38%, and Serbs formed a vast majority among them. Just under 33% of the population were Hungarians, almost 24% were Germans, and 5% were Romanians. Serbs named the collective territories of Baranja, Bačka and Banat Vojvodina. There was a significant territorial overlap of Bačka and Banat with the historical crownland of the Austrian Empire named the Voivodeship of Serbia and Banat of Temeschwar. The crownland was established by Emperor Franz Joseph I as a reward for Serbian services to the empire in quelling of the Hungarian Revolution of 1848 and returned to Hungary a decade later as a step towards the Austro-Hungarian Compromise.
Prelude
Vojvodina's Serbs were predominantly supportive of leaving Austria-Hungary, but were divided on the method – through the National Council in Zagreb or through close ties with Serbia. A meeting was held in Subotica on 2 October on the initiative of , secretary of the Matica srpska. It produced a resolution endorsing unification of the South Slavs, expressing the frustration of the Serbs and the Croats in Bačka, Banat, and Baranya with Hungarian rule, and declaring support of the work of the National Council in Zagreb. Another meeting was convened in Subotica on 23–24 October to implement the resolution. At the meeting, writer Vasa Stajić was appointed a member of the National Council in Zagreb as the representative of Vojvodina. Early support for the National Council was replaced by the view that the territories should be annexed by Serbia outright. The annexation was championed by Jaša Tomić of the Serb People's Radical Party, who believed that the move would strengthen Serbian position in negotiations with the National Council. Tomić supported Hungarian government until the conference held in Subotica on 27 October, where his party decided to reverse course.
The short-lived autonomous Banat Republic, nominally within Hungary, was declared in the region of Banat. On 1 November, the Banat National Council led by Otto Roth proclaimed the republic in Timișoara, relying on support from the Hungarian and German communities. Two days later, on 3 November, the Serbian National Committee was established in the Matica srpska building in Novi Sad. On the basis of information learned through private contacts by , the body concluded that withdrawal of Austro-Hungarian troops from the region was imminent and decided to take power once it occurred, dispatching a delegation headed by Pavlas to Belgrade to request deployment of the Royal Serbian Army to Vojvodina.
Military takeover
On 2 November, Serbian Prime Minister Nikola Pašić, after learning of the imminent signing of the Armistice of Villa Giusti to end the hostilities with Austria-Hungary, told Field Marshal Živojin Mišić, Chief of the Serbian General Staff, that the Serbian forces should occupy parts of Austria-Hungary, including Banat, Syrmia, and Bosnia. The following day, Mišić informed Field Marshal Petar Bojović that the Romanians might attempt to capture Banat and that he thought it necessary to pre-empt such a move by advancing to the Bela Crkva – Vršac – Timișoara line. Two days later, the Serbian supreme command, located at Niš at the time, accepted Mišić's idea, specifying that the army should advance further East from that line. The same day, the Serbian army crossed the Danube at Kovin, establishing a bridgehead in Banat. General Louis Franchet d'Espèrey, as the commanding officer of the Allied Army of the Orient, learned of Armistice of Villa Giusti. When he asked Paris for instructions how to proceed, he was told to continue negotiations with Hungarian representatives on a separate armistice. The Serbian army slowed down the negotiations by delaying deliveries of telegrams between the negotiators and the supreme command to allow its troops to capture territory desired by Regent Alexander.