14th century
The Dečani Charter from 1330 contained detailed list of households and chartered villages in Metohija and northwestern Albania:
3 of 89 settlements were Albanian, the other being non-Albanian.
Out of the 2,166 farming homesteads and 2,666 houses in cattle-grazing land, 44 were registrated as Albanian (1,8%). Others were registered as Slavic mostly Serbian.
The non-Serbian population of Kosovo didn't exceed 2% by the end of the 14th century.
 15th century
1455: Turkish cadastral tax census (defter) of the Brankovic dynasty lands (covering 80% of present-day Kosovo) recorded 480 villages, 13,693 adult males, 12,985 dwellings, 14,087 household heads (480 widows and 13,607 adult males). Totally there were around 75,000 inhabitants in 590 villages comprising modern-day Kosovo. By ethnicity:
12,985 Serbian dwellings present in all 480 villages and towns
75 Vlach dwellings in 34 villages
46 Albanian dwellings in 23 villages
17 Bulgarian dwellings in 10 villages
5 Greek dwellings in Lauša, Vučitrn
1 Jewish dwelling in Vučitrn
1 Croat dwelling
1487: A census of the House of Branković Ottoman
16,729 Christian housing (412 in Priština and Vučitrn)
117 Moslem households (94 in Priština and 83 in rural areas)
City of Ipek - 68% Slavs
121 Christian household
33 Moslem households
Suho Grlo and Metohija:
131 Christian household of who 52% in Suho Grlo were Slavs
Donja Klina - 50% Slavs
Dečani - 64% Slavs
6,124 Christian housings (99%)
55 Moslem houses (1%)
 17th - 18th century
The Great Turkish War of 1683-1699 between the Ottomans and the Habsburgs led to the flight of a substantial part of Kosovan Serbian population to Austrian held Vojvodina and the Military Frontier - about 60-70,000 Serb refugees total settled in the Habsburg Monarchy in that time of whom many were from Kosovo. Following this an influx of Catholic Albanian from the highlands (Malesi) occurred, mostly into Metohija. The process continued in 18th century.
The same was repeated during the Second Migration of Serbs in 1737.
 19th century
19th century data about the population of Kosovo tend to be rather conflicting, giving sometimes numerical superiority to the Serbs and sometimes to the Albanians. The Ottoman statistics are regarded as unreliable, as the empire counted its citizens by religion rather than nationality, using birth records rather than surveys of individuals.
A study in 1838 by an Austrian physician, dr. Joseph Müller found Metohija to be mostly Slavic (Serbian) in character. Müller gives data for the three counties (Bezirke) of Prizren, Peć and Đakovica which roughly covered Metohija, the portion adjacent to Albania and most affected by Albanian settlers. Out of 195,000 inhabitants in Metohija, Müller found:
114,000 Muslims (58%):
c. 38,000 are Serbs (19%)
c. 76,000 are Albanians (39%)
73,572 Eastern Orthodox Serbs (38%)
5,120 Roman Catholic Albanians (3%)
2,308 other non-Muslims (Janjevci etc.)
Müller's observations on towns:
Peć: 11,050 Serbs, 500 Albanians
Prizren: 16,800 Serbs, 6150 Albanians
Đakovica: majority of Albanians, surrounding villages Serbian
Map published by French ethnographer G. Lejean in 1861 shows that Albanians lived on around 57% of the territory of today's province while a similar map, published by British travellers G. M. Mackenzie and A. P. Irby in 1867 shows slightly less; these maps don't show which population was larger overall.
A study done in 1871 by Austrian colonel Peter Kukulj for the internal use of the Austro-Hungarian army showed that the mutesarifluk of Prizren (corresponding largely to present-day Kosovo) had some 500,000 inhabitants, of which:
318,000 Serbs (64%),
161,000 Albanians (32%),
10,000 Romas (Gypsies) and Circassians
Miloš S. Milojević travelled the region in 1871-1877 and left accounts which testify that Serbs were majority population, and were predominant in all cities, while Albanians were minority and lived mostly in villages. According to his data, Albanians were majority population in southern Drenica (Muslim Albanians), and in region around Djakovica (Catholic Albanians), while the city was majorly Serbian. He also recorded several settlements of Turks, Romas and Circassians.
It is estimated that around 400,000 Serbs were cleansed out of the Vilayet of Kosovo between 1876 and 1912 , especially during the Greek-Ottoman War in 1897.
Maps published by German historian Kiepert in 1876, J. Hahn and Austrian consul K. Sax, show that Albanians live on most of the territory of today's province, however they don't show which population is larger. According to these, the regions of Kosovska Mitrovica and Kosovo Polje were settled mostly by Serbs, whereas most of the terrirory of western and eastern parts of today's province was settled by Muslim Albanians.
An Austrian statistics published in 1899 estimated:
182,650 Albanians (47.88%)
166,700 Serbs (43.7%)
Remaining 8.42% Tsintsars, Turks, Circassians, Romas and Jews
At the end of the 19th century, Spiridon Gopchevich, an Autrian traveller - comprised a statistics and published them in Vienna. They established that Prizren had 60,000 citizens of whome 11,000 were Christian Serbs and 36,000 Moslem Serbs. The remaining population were Turks, Albanians, Tzintzars and Gypsies. For Pec he said that it had 2,530 households of which 1,600 were Mohammedan, 700 Christian Serb, 200 Catholic Albanian and 10 Turkish.
 20th century
British journalist H. Brailsford estimated that two-thirds of the population of Kosovo was Albanian and one-third Serbian. The most populous western districts of Djakovica and Pec were said to have between 20,000 and 25,000 Albanian households, as against some 5,000 Serbian ones. Map of Alfred Stead, published in 1909 , shows that similar numbers of Serbs and Albanians were living in the territory.
German scholar Gustav Weigand gave the following statistical data about the population of Kosovo, based on the pre-war situation in Kosovo in 1912:
Prishtina District: 67% Albanians, 30% Serbs
Prizreni District: 63% Albanians, 36% Serbs
Vučitrn District: 90% Albanians, 10% Serbs
Ferizaj (Uroševac) District: 70% Albanians, 30% Serbs
Gilani (Gnjilane) District: 75% Albanians, 23% Serbs
Mitrovica District: 60% Serbs, 40% Albanians
Metohija with the town of Đakovica (Gjakova) is furthermore defined as almost exclusively Albanian by Weigand.