Based on the results of a referendum held on 21 May 2006, Montenegro declared independence on 3 June 2006. Montenegro became the 192nd member state of the United Nations on 28 June 2006. Before its independence, after the end of the former Yugoslavia (Socialist Federal Republic of Yugoslavia) in 1991, Montenegro was part of the Federal Republic of Yugoslavia (together with Serbia), which was in 2003 reformed in the State Union Serbia and Montenegro.  In 2003, 63.5% of the population in Montenegro declared Serbian to be their mother tongue and 22% declared the Montenegrin language. Along with the campaign for independence of Montenegro, a movement for recognition of the Montenegrin language, as separate from Serbian, has emerged. With this movement, some Montenegrin linguistics experts followed the linguistic diversity in the area of the former Yugoslavia and the theory that Montenegrin is its own language. After Serbo-Croatian / Croatian-Serbian, the language used in the former Yugoslavia, split into Serbian, Croatian and Bosnian (Bosniak), .Montenegrin is the IV own language.  Most Montenegrins belong to the Serbian Orthodox Church (Srprska Pravoslavna Crkva - SPC), whose presence on the territory dates to early medieval times. However, there is also the Montenegrin Orthodox Church (Crnogorska Prvoslavna Crkva - CPC) that despite having declared independence from the Serbian Orthodox Church is not recognised by other Orthodox churches. The exact number of followers of the CPC is not known exactly, but after the independence of Montenegro in 2006, there is a tendency for those who were for Montenegrin independence to belong to the CPC. The Roman Catholic Church has a stronger influence in the Adriatic cities where Croats live, but also in cities with Albanian population, in the border area between Montenegro and Albania. Muslims belong to part of the Albanian  and to the Bosnian (Bosniak) population.  

Ethnic composition of the most important ethnic groups in Montenegro, according to the 2003 census, is: Montenegrins 267 669 (43.16%), Serbs 198 414 (31.99%), Bosniaks 48 184 (7.77%), Albanians 31 163 (5.03%), Muslims 24 625 (3.97%), Croats 6 811 (1.1%), Roma/Egyptians/Ashkalis 2 826 (0.46%), and Yugoslavs 1 860 (0.30%). The total population of Montenegro was 620 145. Montenegrin and Serb identities within the censuses in Montenegro are not always exclusive groups, and the size of each group varies with each census, due to political developments in Montenegro