Kosovo was part of the Ottoman Empire from 1455 to 1912, at first as part of the eyalet of Rumelia, and from 1864 as a separate Kosovo Vilayet.
During this period several administrative districts (known as sanjaks ("banners" or districts) each ruled by a sanjakbey (roughly equivalent to "district lord") have included parts of the territory as parts of their territories.
During the Great Turkish War (1683–99), in October 1689, a small Habsburg force under Margrave Ludwig of Baden breached the Ottoman Empire and reached as far as Kosovo, following their earlier capture of Belgrade. Many Serbs and Albanians pledged their loyalty to the Austrians, some joining Ludwig's army. This was by no means a universal reaction; many other Serbs and Albanians fought alongside the Ottomans to resist the Austrian advance. A massive Ottoman counter-attack the following summer drove the Austrians back to their fortress at Niš, then back to Belgrade, then finally back across the Danube into Austria.
The Ottoman offensive was accompanied by savage reprisals and looting, prompting many Serbs – including Arsenije III, Patriarch of the Serbian Orthodox Church – to flee along with the Austrians. This event has been immortalised in Serbian history as the Great Migrations of the Serbs, regarded an alleged huge exodus of hundreds of thousands of Serbs from Kosovo and Serbia proper.
By 1878 Kosovo (in whole or in part) had become the subject of Albanian, Serbian and Montenegrin irredentism (all alongside other regions relevant to each nation). Kosovo's population from these three groups had begun taking steps to oust the then-Ottoman authorities from the region.
In 1878, the League of Prizren was created by Albanians from four vilayets including the Vilayet of Kosovo. The League's purpose was to resist Ottoman rule and incursions by the newly emerging Balkan nations.