The Slavic Congresses
The idea of South Slavic political unification was surely a part of a broader pan-Slavic movement and ideology. If from nothing else, it can be proved from a very fact that the official flag of all kind of Yugoslavia (from 1918 to 2003) was, in fact, an insignia of the 19th century pan-Slavic movement, whose anthem was also used as an official state’s anthem of Socialist Yugoslavia (“Hey Slavs”).
The first clear political expression of an idea of pan-Slavic reciprocity, solidarity, and possible unification was done at the First Slavic Congress held in Prague from May 5th to June 3rd in 1848. It was an important pan-Slavic historical event which fostered an idea of Slavic union and, in particular, the South Slavic solidarity and reciprocity in the Balkans. The Congress deputies decided that the territorial integrity of the Austrian Empire has to be preserved, but at the same time that the national-territorial-administrative autonomies of the Slavic people within the empire should be established and respected by Vienna. A participation in the Congress sessions was taken and by one Yugoslav section composed by the delegates from Slovenia, Croatia, Dalmatia and from Serbian populated areas in South Hungary (a Vojvodina province in present-day Serbia). The Congress received a proposal by the Yugoslav delegation that the Illyrian name for the South Slavs would be replaced by the Yugoslav one.
The first Yugoslav Congress (of the South Slavs from Austria-Hungary) was held in Leibach (Ljubljana) from December 1st to December 3rd, 1870. The focal congress’ decision was that the Austro–Hungarian South Slavs should negotiate with the Hungarians upon the modification of the existing Austro–Hungarian dual system (established in 1867). According to this Austro-Yugoslav proposal, a dual (Austro–Hungarian) federal system had to be transformed into the triple federal system (the Austro–Hungarian–Slavic) by the recognition of a separate Slavic part as an autonomous federal unit within the Habsburg domains. At the same time, a leading political party in Croatia, Slavonia and Dalmatia – a Croatian National Party, issued a Declaration by which announcing that “the final aim of common desires and work of the Serbs, Bulgarians, Slovenes, and Croats should be their unification into the independent, free, popular and Yugoslav state’s community”.
The Croatian-Serbian Cooperation
After the fall of absolutism in the Austrian Empire, a Yugoslav political unification was championed by Serbia’s prince Mihailo Obrenović III (1860–1868), who worked on a creation of the political-military alliance of the Balkan nations for a war against either the Ottoman Empire or the Austrian Empire what depended on the current geopolitical situation in the region. In fact, this war would take the form of a general Balkan revolution for the national liberation of all South Slavs with the political task to create a Yugoslav Empire from the Alps Mts. to the Black Sea with Serbia as its Piedmont. In essence, prince M. Obrenović’s political design of Yugoslavism had three focal aims:
- To expel the Ottoman Empire from Europe.
- To thwart Austrian imperialistic policy in the Balkans primarily in regard to the Austrian plans to annex a Serb-primarily populated Bosnia-Herzegovina.
- To create a national state of the South Slavs according to the principle, “the Balkans to the Balkan people”.
Undoubtedly, on the ruins of the Ottoman and the Habsburg multinational empires, prince M. Obrenović in the 1860s intended to (re)establish independent Balkan and Sub-Danubian national states and to connect them into a Yugoslav (con)federation being inspired by the unification of Italy in 1859−1861. In other words, as the most significant South Slavic national aim, a Serbia’s prince designed, in a cooperation with the Croatian and Bulgarian national representatives, the creation of a single (con)federal Yugoslav state with Serbia as its political center. His leading geopolitical conviction was that only a territorially great and nationally united state’s organization could be really independent in the Balkans. However, the most prosperous chances to create such a state possessed the South Slavs as the most numerous Balkan people.
It is important to stress that historically the publishing of the first political manifesto on the Yugoslav unification – Srpski narod i njegovo značenje za evropsku civilizaciju (The Serbs and Their Importance for the European Civilization written by Imbro Ignjatijević Tkalac, Leipzig, 1853) was financed by Serbia’s prince M. Obrenović III.
In the 1860’s, a leading Croatian figure working for the matter of South Slavic unification became a Roman Catholic bishop and a Croatian national leader, Josip Juraj Strossmayer, who, in fact, favored as an ultimate political goal a Yugoslav unification within Austria-Hungary in a form of a Greater Croatia. Nevertheless, both Croatian archbishop J. J. Strossmayer and Serbia’s prince M. Obrenović III believed that the Ottoman-ruled South Slavs could achieve their freedom only in the case of a military defeat of the Ottoman Empire in a general war against the Balkan Orthodox Christians, what would be a precondition for the final Ottoman expulsion from the Balkan peninsula and Europe. However, on the other hand, J. J. Strossmayer, in contrast to both prince M. Obrenović and Serbia’s prime minister I. Garašanin, did not think that Austria-Hungary was the main opponent for the achievement of the liberal political and national aims by the Balkan nations and, therefore, he advocated the preservation of the territorial integrity of Austria-Hungary.
A clear expression of the Yugoslav ideology by the Croats occurred in July 1868, when J. J. Strossmayer informed the agent of Serbia’s government that his Croatian National Party believed that the duty of Serbia was to liberate Bosnia-Herzegovina from the Ottoman Empire and, therefore, to create a foundation for the future Yugoslav political unification. A project of the Yugoslav unification designed by the Croatian National Party was in essence based on the idea that in the process of a struggle for the creation of a common Yugoslav state, Serbia should assume a political and Croatia a cultural mission. As a result, according to J. J. Strossmayer, Serbia would be a Yugoslav Piedmont followed by Croatia as a Yugoslav Tuscany.
The “Sub-Danubian Question”
J. Strossmayer, F. Rački, M. Mrazović and the other leaders of the Croatian National Party firstly supported a cultural union of the South Slavs, which would become a basis for their later national and political unification. However, both pro-Yugoslav Serbs and their Croatian counterpart believed that a creation of a common Yugoslav state was the most optimal way to solve a “Yugoslav Question” in the Balkans by the unification of all Serbs and Croats into a single national state and if possible to include the Bulgarians and Slovenes as well. For example, the Croatian National Party’s ideologue, a famous historian Franjo Rački, was convinced that “divided” Croats (who lived in several Austro–Hungarian provinces and Ottoman Bosnia and Herzegovina) could be united and provide for themselves a cultural, national and political independence only in the alliance with other South Slavs.
However, a crucial difference between the Serbian and the Croatian political leaders in regard to the creation of a common South Slavic state was their opposite opinions upon the question who has to play a principal role in this process. The Serbian politicians claimed this role to the Principality of Serbia, while their Croatian counterparts saw the Croats as the principal leaders of the Yugoslav unification. Consequently, according to the prior, Belgrade would be the capital of a united South Slavic state while the latter favored Zagreb as a South Slavic capital after the unification.
During the Serbian-Ottoman diplomatic crises in 1862, a Serbian politician from Vojvodina (Vajdaság), Mihailo Polit-Desančić proposed a political plan for the resolving both the “Eastern Question” and the “Sub-Danubian Question” at the same time. According to the plan, one great Balkan state has to be created gradually in three stages:
1) The Greater Serbia, composed by Bosnia, Herzegovina, Montenegro, Ancient Serbia (Kosovo-Metohija and Raška/Sandžak) and the Principality of Serbia.
2) The Yugoslav Federation, composed by Croatia and Serbia (the demarcation line between Serbia and Croatia would follow Vrbas river in Bosnia).
3) The Balkan Federation, made by the Yugoslav Federation (Serbia and Croatia) and Bulgaria.
The Role of the “Serbian Bismarckism”
A way of thinking by Mihailo Polit-Desančić was tracked by the first Serbian socialist – Svetozar Marković who proposed a similar plan to solve a “Sub-Danubian Question”. He also designed three stages in the process of the creation of a common South Slavic state in the Balkans:
- The creation of federal Serbia.
- A Serbian-Bulgarian federation (or the Yugoslav Federation).
- The Balkan Federation.
A Serbian writer Jovan Skerlić and famous scholar Jovan Cvijić as well favored a Yugoslav federation with Serbia as its central part. One of the most important supporters of the concept of the Yugoslav federation with Belgrade as a capital was a Serbian historian and philologist Stojan Novaković, who expressed his federalist ideas in the article Nakon sto godina (After Hundred Years, 1911).
Actually, all of these mentioned Serbian politicians and scholars saw Serbia as the Piedmont of either Yugoslavs (the South Slavs without Bulgarians) or all South Slavs (the Yugoslavs with Bulgarians). Belgrade, therefore, had to play a role of the “Serbian Bismarckism”. Their focal arguments were based on the next three facts:
1) Only the Serbs created up to that time free South Slavic states – Serbia and Montenegro.
2) The Serbs had been in majority among all South Slavs and particularly among the Yugoslavs.
3) The Serb-populated lands had the biggest economic potentials and natural resources among all South Slavic territories.
There were many variations of the project of the unification of the South Slavic or Yugoslav lands towards the end of the 19th century. For example, a Serbian writer Milan Milojević in 1881 published a map of de facto a Greater Serbia, but under the name of a Greater Yugoslavia. According to him, a Greater Yugoslavia should embrace the following territories: a geographic-historical Macedonia (up to Thessaly), whole Banat (eastward to Arad), Bačka (northward to Szeged), and all Croatian and Slovenian lands including Carinthia, Trieste and some territories beyond Isonzo river. Such borders of future Yugoslavia were also accepted by the Serbs P. Niketić in 1890 and D. Putniković in 1896 but without Slovenian lands. However, in all of such projects of a Greater Yugoslavia, Serbia was seen as a Yugoslav Piedmont with Belgrade as the “Serbian Bismarckism”.
 Milorad Ekmečić, Stvaranje Jugoslavije 1790–1918, vol. I, Beograd, 1989, pp. 535–536.
 Dr. Jaroslav Šidak, Dr. Mirjana Gross, Dr. Igor Karaman, Dragovan Šepić, Povjest hrvatskog naroda 1860–1914, Zagreb, 1968, p. 45.
 Milorad Ekmečić, Stvaranje Jugoslavije 1790–1918, vol. II, Beograd, 1989, p. 235.
 Vladimir Ćorović, Borba za nezavisnost Balkana, Beograd, 1937, pp. 99−100; Simo C. Ćirković, Knjaz Mihailo Obrenović. Život i politika, Beograd, 1997, p. 203.
 Vasa Čubrilović, Istorija političke misli u Srbiji XIX v., Beograd, 1958, pp. 222–223.
 An agreement between the Serbian government and the Bulgarian Revolutionary Committee, signed in Romania in 1867, anticipated a creation of the Yugoslav Empire. In fact, the Serbian-Bulgarian federation had to be created under the government of Serbia’s Obrenović dynasty. According to the agreement between Serbia and Montenegro, Montenegro’s prince Nikola I Petrović would abdicate in Serbia’s prince M. Obrenović’s favor in the case of political unification of Serbia and Montenegro [Vasa Čubrilović, Istorija političke misli u Srbiji XIX v., Beograd, 1958, pp. 225–227; Grgur Jakšić, Vojislav Vučković, Spoljna politika Srbije za vreme vlade kneza Mihaila (Prvi balkanski savez), Beograd, 1963, pp. 281–287, 362–369, 452–455].
 Milorad Ekmečić, Stvaranje Jugoslavije 1790–1918, vol. II, Beograd, 1989, p. 148.
 Vasilije Đ. Krestić, Biskup Štrosmajer u svetlu novih izvora, Beograd, 2002.
 Vasilije Đ. Krestić, Srpsko-hrvatski odnosi i jugoslovenska ideja u drugoj polovini XIX veka, Beograd, 1988, p. 136.
 Milorad Ekmečić, Stvaranje Jugoslavije 1790–1918, vol. II, Beograd, 1989, pp. 238–239.
 Dr. Hans Schrekeis, “Introduction” in the collection by Anton Zollitsch, Josef Georg Strossmayer. Beiträge zur konfessionellen Situation Österreich-Ungarns im ausgehendem 19. Jahrhundert und zur Union sbemühung der Slawen bis in die Gegenwart, Salzburg, 1962, p. 5.
 This division of roles on “Serbian Piedmont” and “Croatian Tuscany” was made by J. J. Strossmayer in his letters to the British prime minister [R. W. Seton-Watson, The Southern Slav question and the Habsburg Monarchy, London, 1911, p. 420, “The letter sent to Gladstone on October 1st, 1876”; James Bukowski, “Jugoslavism and the Croatian National Party in 1867”, Canadian Review of Studies in Nationalism, 3, 1, 1975, p. 74].
` Vasilije Đ. Krestić, Srpsko-hrvatski odnosi i jugoslovenska ideja u drugoj polovini XIX veka, Beograd, 1988, p. 134.
 Vasa Čubrilović, Istorija političke misli u Srbiji XIX v., Beograd, 1958, pp. 258–262.
 ibid, pp. 300–313; Dragan Simeunović, Iz riznice otadžbinskih ideja. Slobodarski međaši naše političke misli 19. veka, Beograd, 2000, pp. 83−140.
 Vasa Čubrilović, Istorija političke misli u Srbiji XIX v., Beograd, 1958, p. 393.
 John B. Allcock claims that Nikola Pašić was the first among them [John B. Allcock, Explaining Yugoslavia, New York, 2000, p. 221].
 P. M. Niketić, Srpski svet u reči i slici, Beograd, 1890, p. 3; D. J. Putniković, Đakovanje i carevanje, knjiga za mladež, Beograd, 1896, p. 102.