Emperor Stefan Uroš IV Dušan "the Mighty" (r. 1331–55) was succeeded by his son Stefan Uroš V "the Weak" (r. 1355–71), whose reign was characterized by the decline of central power and the rise of numerous virtually independent principalities; this period is known as the fall of the Serbian Empire. Uroš V was neither able to sustain the great empire created by his father nor repulse foreign threats and limit the independence of the nobility; he died childless on 4 December 1371, after much of the Serbian nobility had been destroyed by the Ottomans in the Battle of Maritsa earlier that year. Prince Lazar, ruler of the northern part of the former empire of (Moravian Serbia), was aware of the Ottoman threat and began diplomatic and military preparations for a campaign against them.
After the defeat of the Ottomans at Pločnik (1386) and Bileća (1388), Murad I, the reigning Ottoman sultan, moved his troops from Philippoupolis to Ihtiman (modern Bulgaria) in the spring of 1388. From there they traveled across Velbužd and Kratovo (modern R. Macedonia). Though longer than the alternative route through Sofia and the Nišava Valley, this led the Ottoman forces to Kosovo, one of the most important crossroads in the Balkans. From Kosovo, they could attack the lands of either Prince Lazar or Vuk Branković. Having stayed in Kratovo for a time, Murad and his troops marched through Kumanovo, Preševo and Gnjilane to Priština, where he arrived on June 14.
While there is less information about Lazar's preparations, he gathered his troops near Niš, on the right bank of the South Morava. His forces likely remained there until he learned that Murad had moved to Velbužd, whereupon he moved across Prokuplje to Kosovo. This was the best place he could choose as a battlefield, as it gave him control of all the routes that Murad could take.
Reliable historical accounts of the battle are scarce; however, a critical comparison with historically contemporaneous battles (such as Ankara or Nikopolis) enables reliable reconstruction.