The Serbian state disintegrates as a result of the Battle of Kosovo Polje in 1389, in which a combined army of Serbs, Albanians, and Hungarians, led by the Serb knez, or prince, Lazar Hrebeljanovic, and including a large Bosnian contingent, is crushingly defeated by the Ottomans; Lazar dies by execution; Ottoman Sultan Murad by assassination.

Montenegro achieves independence from Serbia.

The Serbian states in the north and south come under the control of petty despots who rule as Ottoman vassals.

To the north, Hungary alone is in a position to resist further Muslim advances; Moldavia falls to Polish control.

South of the Danube, after Wallachia accepts Ottoman vassalage, only Bosnia, Venetian Albania, Greece, and the Serbian fort of Belgrade remain outside Ottoman rule.

Serb despots, forced to accept the position of vassals to the Turks, continue to rule a diminished state of Raska, at first from Belgrade.