The colonisation of Kosovo was a programme implemented by the Kingdom of Yugoslavia during the interwar period (1918–1941) with the aim of altering the ethnic population balance in the region where Albanians formed an ethnic majority. During the colonisation period, between 60,000 and 65,000 colonists, of whom over 90% were Serbs, settled on the territory of the former Kosovo Vilayet captured from the Ottoman Empire in 1912. Along with the Serb colonisation, a policy of forced migration of ethnic Albanians was attempted, enlisting the participation of Turkey.
Some Serb colonisation of Kosovo took place during the Balkan Wars (1912-1913). Government sponsored colonisation was initiated in 1920 when the assembly of the Kingdom of Yugoslavia passed the Decree on the Colonisation of the Southern Provinces of Yugoslavia, while the second began in 1931, when the Decree on the Colonisation of the Southern Regions was issued. Former soldiers and chetniks were offered incentives to settle in Kosovo, although this phase of the colonisation is considered unsuccessful because only 60 to 70 thousand people showed a willingness to become settlers, of whom many failed to follow through.
From 1918 to 1921, expulsions of the Albanian population reduced its numbers from around one million to about 439,500. In the 1930s, Yugoslavia signed treaties with Turkey (which were never implemented) providing that Turkey, with Islam as the major religion, would accept expellees; Albanians have a Muslim community, although highly secularized. One treaty signed in 1935 undertook the transfer of about 200,000 Albanians while a second treaty signed in 1938 undertook the transfer of 40,000 Albanian families.
The table shows the total number of registered settlers in each Kosovo county:
In 1937, a Serbian nationalist intellectual, Vaso Čubrilović, who had been one of the plotters of the assassination of Austrian Archduke Franz Ferdinand, proposed the expulsion of all Albanians: