The Serbian forces in this celebrated battle against the Turks probably comprised 15-25,000 men, including about 5,000 infantry and apparently some artillery, this army being composed of Bosnians (under Vlatko Vukovic), Albanians and others in addition to Serbians, under the overall command of Prince Lazar. They drew up facing south-east with their centre commanded by Lazar, their right wing under his son-in-law Vuk Brankovic, and their left wing primarily of Bosnians under Vukovic. Their cavalry were drawn up behind a screen of archers, and more infantry were to their rear. The Ottomans, probably numbering between 27-40,000 men, similarly drew up with archers to the fore, along with their other infantry, with a deep, stake-implanted ditch behind them covered with undergrowth (this on the Ottoman centre and left only), their cavalry forming the rear line. Sultan Murad himself commanded the centre, with his sons Bayezid, beylerbey of Rumelia, and Yaqub Celebija, beylerbey of Anatolia, on the right and left respectively (Doukas transposes their positions). In addition camels had been introduced into their battle-line to frighten the Serbian horses.
The battle began at daybreak and lasted 4 hours (i. e. up until 9 a. m.). It appears to have been opened by the Serbs with artillery and arrow fire, and the Ottomans replied in kind and then charged. Their first attack, executed by 2,000 archers, possibly supported by cavalry, was held and even driven back, particularly on the left where Brankovic’s troops charged down from the vantage of higher ground. It was probably during the bloody melee that ensued that a certain Milos Kobilic, pretending to desert, penetrated to Murad’s command post and stabbed the sultan to death. However, the Serbian advance, pushing back the Ottoman centre and left, had meanwhile foundered on the defensive ditch, where the Serbs suffered heavily from archery, and Bayezid, having assumed command, now counter-attacked their centre, which wavered as the Turkish left, then their centre, rallied and with other stragglers returned to the fray. After further hard fighting the Ottoman superiority in numbers began to tell, and Serbian resistance began to collapse. According to legend Brankovic’s right wing (allegedly, but highly improbably, comprised of 12,000 men) either deserted or broke in rout, but actually it withdrew only when its position had become untenable. One 15th century source says that it was in fact a certain Dragosav Probic who deserted, going over to the Turks, upon hearing of which Vukovic and the Bosnians fled. Either way, other units began to follow suit and the whole Serbian line disintegrated.
Losses on both sides had been heavy, and it was such a Pyrrhic victory for the Turks that for a while the battle was celebrated in Western Europe as a Serbian success. Philippe de Mezieres wrote that each side suffered 20,000 casualties, while a Florentine chronicle says 30,000 Serbs and 50,000 Turks died in the battle. Prince Lazar and many other Serbian leaders were captured and executed, while on the Ottoman side both Murad and Yaqub Celebija had been killed, the latter by Bayezid himself as soon as he heard of his father’s death in order to remove a potential rival for the throne.