Serbian nationalism during the 19th Century
With the nation-building process in mid-19th century, first Croatian-Serbian tension appeared. Serbian minister Ilija Garašanin's Načertanije (1844):3 claimed lands that were inhabited by Bulgarians, Macedonians, Albanians, Montenegrins, Bosnians, Hungarians and Croats were part of Serbia.:3 Garašanin's plan also includes methods of spreading Serbian influence in the claimed lands.:3–4 He proposed ways to influence Croats, who Garašanin regarded as "Serbs of Catholic faith".:3 This plan considered surrounding peoples to be devoid of national consciousness.:3–4:91 Vuk Karadžić in the 1850s then denied the existence of Croatians and Croatian language, counting them as "Catholic Serbs". Croatia was at the time a kingdom in Habsburg Monarchy, with Dalmatia and Istria being separate Habsburg Crown lands. Ante Starčević, head of the Croatian Party of Rights, advocated for Croatia as a nation. After Austro-Hungary occupied Bosnia and Herzegovina in 1878 and Serbia gained its independence from Ottoman Empire, Croatian and Serbian relations deteriorated as both sides had pretensions on Bosnia and Herzegovina. In 1902 there was a reprinted article written by Serb Nikola Stojanović that was published in the publication of the Serbian Independent Party from Zagreb titled Do istrage vaše ili naše (Till the Destruction, ours or yours) in which denying of the existence of Croat nation as well as forecasting the result of the "inevitable" Serbian-Croatian conflict occurred.
That combat has to be led till the destruction, either ours or yours. One side must succumb. That side will be Croatians, due to their minority, geographical position, mingling with Serbs and because the process of evolution means Serbhood is equal to progress.
— Nikola Stojanović, Srbobran, 10.08.1902.
During the 19th century, some Italian radical nationalists tried to promote the idea that a Croatian nation has no sound reason to exist: therefore the Slavic population on the east coast of the Adriatic Sea (Croats and Slovenes) should be Italianized, and the territory included in Italy.