Serbian nationalism asserts that Serbs are a nation and promotes the cultural and political unity of Serbs. It is an ethnic nationalism, originally arising in the context of the general rise of nationalism in the Balkans under Ottoman rule, under the influence of Serbian linguist Vuk Stefanović Karadžić and Serbian statesman Ilija Garašanin.Serbian nationalism was an important factor during the Balkan Wars which contributed to the decline of the Ottoman Empire, during and after World War I when it contributed to the dissolution of the Austro-Hungarian Empire, and again during the breakup of Yugoslavia and the Yugoslav Wars of the 1990s.
After 1878, Serbian nationalists merged their goals with those of Yugoslavists, and emulated the Piedmont's leading role in the Risorgimento of Italy, by claiming that Serbia sought not only to unite all Serbs in one state, but that Serbia intended to be a South Slavic Piedmont that would unite all South Slavs in one state known as Yugoslavia. Serbian nationalists supported a centralized Yugoslav state that guaranteed the unity of the Serbs while resisting efforts to decentralize the state. The Vidovdan Constitution adopted by Yugoslavia in 1921 consolidated the country as a centralized state under the Serbian Karađorđević monarchy. Croatian nationalists opposed the centralized state and demanded decentralization and an autonomous Croatia within Yugoslavia, which was accepted by the Yugoslav government in the Cvetković–Maček Agreement of 1939. Serbian nationalists opposed the agreement on the grounds that it weakened the unity of Serbdom, asserting its importance to Yugoslavia with the slogan "Strong Serbdom, Strong Yugoslavia". The invasion and partition of Yugoslavia in World War II resulted in violent ethnic conflict between nationalist Serbs, Croats, Bosniaks, and others, resulting in a highly violent sectarian variant of Serbian nationalism rising in the Chetnik movement.