The Battle of Kosovo took place on 15 June 1389 between an army led by the Serbian Prince Lazar Hrebeljanović and an invading army of the Ottoman Empire under the command of Sultan Murad I. It was one of the largest battles of the Late Middle Ages.
The battle was fought on the Kosovo field in the territory ruled by Serbian nobleman Vuk Branković, in what is today Kosovo, about 5 kilometers (3.1 mi) northwest of the modern city of Pristina. The army under Prince Lazar consisted mostly of his own troops, a contingent led by Branković, and a contingent sent from Bosnia by King Tvrtko I, commanded by Vlatko Vuković. Additionally, Lazar was also supported by a Christian coalition from various European ethnic groups. Prince Lazar was the ruler of Moravian Serbia and the most powerful among the Serbian regional lords of the time, while Branković ruled the District of Branković and other areas, recognizing Lazar as his overlord.
Reliable historical accounts of the battle are scarce. The bulk of both armies were wiped out, and Lazar and Murad were killed. Murad's assassination is attributed to a Serbian knight named Miloš Obilić. The battle marked the only time in history when an Ottoman Sultan was killed in battle. Serbian manpower was depleted and had no capacity to field large armies against future Ottoman campaigns, which relied on new reserve forces from Anatolia. The Serbian principalities that were not already Ottoman vassals, became so in the following years.
The mythologization of the battle and writings began shortly after the event, though the legend was not fully formed immediately after the battle but evolved from different originators into various versions. In Serbian folklore, the Kosovo Myth acquired new meanings and importance during the rise of Serbian nationalism in the 19th century as the Serbian state sought to expand, especially towards Kosovo which was still part of the Ottoman Empire. In modern discourse, the battle would come to be seen as integral to Serbian history, tradition and national identity. Vidovdan is celebrated on June 28 and is an important Serbian national and religious holiday as a memorial day for the Battle of Kosovo.
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 in 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 North 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 Gjilan to Pristina, where he arrived on 14 June.
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. The historiographical examination of the battle is challenging. No first-hand accounts from participants in the battle exist. Contemporary sources are written from widely diverging points of view and not much is discussed in them about battle tactics, army size and other battleground details.
Many details regarding the Battle of Kosovo are uncertain. The composition of both armies is a matter of scholarly dispute, and there exists no reliable information on the topic. Nonetheless, the battle of Kosovo was one of the largest battles of the late medieval times, regardless of the exact army size. Estimates about the sizes of both armies vary, but it is generally believed that the Ottoman army was larger. The leading estimate accepted by Western scholars is that Lazar's army contained 15,000-20,000 troops, whilst Murad's army consisted of 27,000–30,000. A higher estimate suggests a total of 40,000 troops for the Ottomans and 25,000 for Lazar's coalition.
Ottoman historian Mehmed Neşri, who authored the first detailed report in Ottoman historiography about the battle of Kosovo in 1521, placed the size of the Christian coalition at around 500,000, claiming that it was double the size of the Ottoman army. Neşri was presenting an Ottoman imperial narrative, and considering the fact that an Ottoman Sultan died during the battle, Ottoman sources typically exaggerate the size of the Christian army. According to historian Noel Malcolm, Ottoman writers were most likely eager to build up the size and significance of Lazar's army, which they described as vastly outnumbering Murat's, in order to add to the glory of the "Turkish victory", and it is generally agreed that the Ottoman sources contain exaggerations in favour of the Ottomans. The first known European and Ottoman accounts on the battle in general are strongly influenced by the long-term political consequences of increasing Ottoman conquest, and none of these narratives form a credible basis for the reconstruction of the battle itself, regardless of the author's origins. Contemporary documents were not heavily concerned about the details surrounding the size of both armies, their tactics, their armaments, and the course of the battle, and European reports were mostly focused on the death of Murad and a supposed Christian victory. Additionally, the earliest Serbian sources for the Battle of Kosovo were more so the product of religious rhetoric than historical data, and they are not useful in providing particular details on the battle. Ultimately, every contemporary account of the battle has been composed under various influences of a religious, political, and literary nature, and scholars can only try and distinguish or trace some of the early strands of tradition which were to eventually become part of the Kosovo Myth to reach any sort of conclusion.
The Ottoman army was reinforced by their Muslim vassals and allies from Anatolia, having been supported by auxiliary troops from the Anatolian Turkoman Beylik of Isfendiyar, Murad's army comprised no more than 2,000 Janissaries. Additionally, Murad's army consisted of as many as 8,500 cavalrymen, Both armies contained soldiers of various origins, and the Ottomans were reinforced by their Christian vassals. The Ottoman army likely included a substantial number of non-Turkish contingents, among whom were the forces of two regional Serbian rulers, Marko Kraljević and Konstantin Dejanović, who governed parts of Macedonia and Bulgaria as Ottoman vassals. As a condition of their vassalage, they were obliged to provide troops, and it is generally assumed that they did so and that either one or both rulers personally took part in the battle on the Ottoman side. As suggested by contemporary chronicles and events involving John VII Palaiologos, Greek and Genoese soldiers may also have taken part in the battle as part of the Ottoman army, and it is possible that some Albanians fought on the Ottoman side as well.
The main forces of Lazar's coalition included the Serbian contingent from his own principality, troops brought by his son-in-law, Vuk Branković, and Bosnian forces under Vlatko Vuković, sent by Lazar's ally King Tvrtko of Bosnia. While the great majority of Lazar's army were Serbs, it also included a coalition of Albanians, Croatians, Hungarians, Vlachs and Bulgarians. Some contemporary Ottoman sources have also claimed that the Czechs and other western Europeans also fought on Lazar's side. Historian Dejan Djokić initially noted that Bosnians, Bulgarians, Albanians, Vlachs, and Hungarians are believed to have participated in Lazar’s army in addition to the predominantly Serbian forces. He later considered it improbable that Lazar led a broad coalition that included Albanians, Bulgarians, Czechs, Hungarians, Germans, and Vlachs, alongside the Serbian and Bosnian troops. Historian Daniel Waley has stated that next to nothing can be said with assurance about the numbers and multi-ethnic composition of both armies.