Serbianisation or Serbianization, also known as Serbification, and Serbisation or Serbization ( or ; ; or ; ; ) is the spread of Serbian culture, people, and language, either by social integration or by cultural or forced assimilation.

Medieval period

Populated by Bulgarians and Romanians, the area between the Morava and Timok rivers became part of the Serbian state in 1291/1292 which began the Serbianisation of the region. "An important Romanian concentration existed in the region between the Timok and Morava Rivers.... This region was taken by Serbia in 1291 or 1292 from two Cuman chiefs, Darman and Kudelin, that were first under Hungarian vassalage. Only then did the Serbianization of this region previously peopled by Romanians and Bulgarians begin." Albanians that came under the rule of Serb Emperor Stefan Dušan were required by state policy to convert to Orthodoxy and Serbianise their Albanian names. Uglješa Mrnjavčević, a fourteenth-century Serbian despot who ruled much of Macedonia on behalf of Serb Emperor Stefan Uroš V attempted to Serbianise the monastic community of Mount Athos.

19th century Principality of Serbia

The historical sources demonstrate that before the 19th century and the rise of nationalism in the Ottoman Empire the majority of the ordinary Orthodox Christians on the Balkans had only a vague idea of their ethnic identity. The local South Slavic-speaking peasants were accustomed to defining themselves in terms of their religion, locality, and occupation. After the national states were established, peasantry was indoctrinated through the schools and military conscription, the official Church, and the governmental press. It was through these instruments of the state administration, that a national identity came into real and rapid development.K. Bozeva-Abazi, 2003, The shaping of Bulgarian and Serbian national identities, 1800s-1900s. McGill University, Montreal. Summary.

Some Serbian sources from the mid 19th century claimed that the areas southeast of Niš, including Southern Pomoravlje and Macedonia, were mainly Bulgarian populated.The Serbian newspaper Srbske Narodne Novine (Year IV, pp. 138 and 141-43, May 4 and 7, 1841), described the towns of Niš, Leskovac, Pirot, and Vranja as lying in Bulgaria, and styles their inhabitants Bulgarians. In a map made by Dimitrije Davidović called „Territories inhabited by Serbians” from 1828 Macedonia, but also the towns Niš, Leskovac, Vranja, Pirot, etc. were situated outside the boundaries of the Serbian nation. The map of Constantine Desjardins (1853), French professor in Serbia represents the realm of the Serbian language. The map was based on Davidović‘s work placing Serbians into the limited area north of Šar Planina. Per Serbian newspaper, Vidovdan (No. 38, March 29, 1862), the future Bulgarian-Serbian frontier would extend from the Danube in North, along the Timok and South Morava, and then on the ridge of Shar Mountain towards the Black Drin River to the Lake of Ohrid in the South.Ethnic Mapping on the Balkans (1840–1925): a Brief Comparative Summary of Concepts and Methods of Visualization, Demeter, Gábor and al. (2015) In: (Re)Discovering the Sources of Bulgarian and Hungarian History. Hungarian Academy of Sciences, Bulgarian Academy of Sciences, Sofia; Budapest, p. 85.

The region of today's Eastern Serbia faced a number of changes in regard to the dominant population group in the area, due to constant wars, conquests, plague Great Migrations of the Serbs, and Migrations of Bulgarians during the 17thЛюбомир Георгиев. „Българите католици в Трансилвания и Банат (XVIII – първата половина на XIX в.)“, София 2010 г. стр. 21–23. and the 18th-19th century.Дойнов, Стефан. Българите в Украйна и Молдова през Възраждането (1751–1878). София, Академично издателство „Марин Дринов“, 2005. . с. 57–58. It was only after the Serbian revolution and later independence that the Serbian national idea gained monumentum within the area east of Niš.Stevan K. Pavlowitch, Serbia: the history behind the name, 2002 — p. 68.-{Antic.org}-: Изгорео симбол Ниша According to many authors ca. 1850 the delineation between Serbs and Bulgarians ran north of Niš, although Cyprien Robert claimed that Serbs formed half of the town of Niš population. In the sub-district of Prokuplje, the most numerous ethnic group were the Albanians, while in Vranje, Bulgarians and Albanians were equally distributed alongside minority Serbian population. In Pirot and Leskovac sub-districts, the Bulgarians were the main ethnic group. The Turks lived mainly in the bigger towns,According to Boué, who traveled through the region in 1837, Nish was a Bulgarian district and both in the town and in the country Bulgarians formed the great part of the population. Nevertheless, Robert claimed that Serbians formed half of the town population. In the Pirot and Leskovac districts, Bulgarians were the main ethnic group, especially in the villages disseminated on the valleys. In the district of Prekoplie, the main ethnic group was Muslim Albanians. According to Boué, Albanians were placed in the Nish sub-province by the Porte to counterbalance the Christian majority and to prevent periodic Bulgarian rebellions. In Vranje, Bulgarians and Muslim Albanians were equally distributed. Turks lived mainly in the chief towns and formed a small minority in the whole of this sub-province. Bulgarians, Serbians and Muslim Albanians were the main ethnic groups. According to Aubaret the total population in the Nish sub-province was about 355,000. For more see: Engin Deniz Tanır, The Mid-nineteenth Century Ottoman Bulgaria from the Viewpoints of French Travellers (Ph.D. diss, METU, 2005), p. 71. and were later expelled with other Muslim minorities in 1862. In Ottoman usage then the Sanjak of Niš was included in an area designated as "Bulgaristan", i.e. Bulgaria.Mark Pinson, Ottoman Bulgaria in the First Tanzimat Period — The Revolts in Nish (1841) and Vidin (1850), p. 103; Middle Eastern Studies, Vol. 11, No 2 (May, 1975), pp. 103–146.

Serbian elites after the mid of the 19th century, claimed that the Bulgarians located south-east of Niš were Old Serbians, which was an implementation of Garašanin's irredentist plan called Načertanije.: "...a Balkan alliance, which alarmed both Bulgarians and Turks with its implications of Serbian expansionism as expounded two decades previously, in Garasanin's Nacertanie, the Serbian equivalent of Greek Megali Idea." In 1870, the Southern Pomoravlje was included in the Bulgarian Exarchate. Milan Savić still claimed that at this time (1878) Niš and environs were Bulgarian populated. After the war between Russia and the Ottoman Empire (1877–1878), the lands in the regions of Niš, Pirot and Vranje became a part of Serbia. Serbia had successfully homogenized and modernized these new territories and in this way it assimilated the local Bulgarians of the Timok and Morava river valleys toward the end of the nineteenth century. Afterwards Serbia turned its attention to the region of Macedonia.

Kingdom of Serbia In 1878 Serbia became independent and pressure developed in the state for people from different ethnic groups to Serbianise religious denominations and their personal names. Serbianisation of identity along with ideological and cultural Serbianisation followed. Belgrade was reconstructed as a new capital by the Serb elite that removed elements of the Ottoman era. While Serb commonfolk looked for ways to aid the Serb cause and assist other Serbs still residing in areas ruled by the Muslim Ottoman Empire. Austro-Hungarian Serbs who had integrated within Serbia and promoted Serbianisation opened the country up to cultural and economic influences of Austria-Hungary in the 1880s. The demographics of Niš underwent change whereby Serbs who formed half the urban population prior to 1878 became 80 percent in 1884. "Prior to 1878, the Serbs comprised not more than one half of the population of Nis, the largest city in the region; by 1884 the Serbian share rose to 80 per cent."

Principality of Montenegro According to jurist and sociologist Valtazar Bogišić all Eastern Orthodox citizens of Montenegro were Serbs. He states that they Serbianised a small number of Romani people who mostly worked as blacksmiths.

Ottoman Macedonia

Representatives from Serbia, such as the statesmen, diplomat and historian Stojan Novaković encouraged a separate Slavic Macedonian identity to counter the strong Bulgarian influence, to separate the local population from the rest of the Bulgarians, and to instill the "Serbian idea". Serbianising directly the local Slavic population through propaganda and education was difficult due to strong Bulgarian sentiments at the time in the region. The spread and promotion of Serbian Macedonianism was seen by Serbs as the first move toward eventually Serbianing the Macedonians. Serbian nationalist-oriented politicians in the 19th century traveled to the area of Ottoman Macedonia and spread national propaganda with intent to build a Serbian national feeling among the local population. One of these nationalist was Miloš Milojević who claimed that Serbia in ancient times has been far bigger, with expansion to more continents.Darko Gavrilović; (2009) Mitovi nacionalizma i demokratija (in Serbian) p. 30; Centar za istoriju, demokratiju i pomirenje, Novi Sad,

Vlachs

Pre-Ottoman Serbian Empire and its institutions had no time to serbicize the Balkan Vlachs in medieval Serbia, since it soon fell under the Turkish dominance; that process was not finished until the 19th century. Furthermore, the process of serbization, of "Vlachs" has been accomplished through the Serbian Orthodox Church in Dalmatia and the Military Frontiers (Vojna Krajina), i. e., in the territories of the Croatian Kingdom, together with Bosnia, where Vlachs found their final domicile. The Church had the most decisive role in the serbization process of Vlachs in the initial and middle phases. During the 16–18th centuries the amalgamation of the process of sedentarization of the Orthodox Vlachs and their gradual fusion into the Serbian rural population reached a high level and was recognized by the Ottoman authorities. In the final phase, the most significant role was played by the newspaper Srbobran in the 1880s and 1890s.Mirko Valentić;(1992) The ethnic roots of the Croatian and Bosnian Serbs pp. 1–21; Octavian Ciobanu; (2018) The heritage of Western Balkan Vlachs pp. 1–9; According to Ivo Banac almost whole civil authority of the former Serbian state Ottomans transfer to the patriarchs of Peć. The millet system that the Serbs transferred to the Habsburg Monarchy was a good instrument for transmitting the Serbian national identity. Patriarchate of Peć and later Metropolitanate of Karlovci Serbianized parts of Balkan Orthodox people such as Bulgars, "Vlachs", Albanians, Romanians and a significant number of Catholic Croats.Ivo Banac; (1984) The National Question in Yugoslavia: Origins, History, Politics p. 64-66; Cornell University Press, According to Vjeran Kursar although Catholic and Muslim Vlachs, or other, non-Serbian elements which exist in the western Balkans should not be underestimated still the vast majority of Vlachs in that area were Orthodox Christians and Serbian(ised), often still bilingual. All Slavic or Slavicised Orthodox Christians under the jurisdiction of Patriarchate of Peć ie Serbian patriarchs were eventually identified as Serbs, this process did not finish until modern times.Vjeran Kursar; (2013) Being an Ottoman Vlach: On Vlach Identity (Ies), Role and Status in Western Parts of the Ottoman Balkans (15th-18th Centuries) p. 124, 127 Journal of the Center for Ottoman Studies - Ankara University, 24, 34; 115–161 Czamańska Ilona; Vlachs and Slavs in the Middle Ages and Modern Era p. 19; Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej,

20th century Interwar Yugoslavia