The Ottoman army penetrated Pomoravlje and neighbouring areas, killing and looting, then clashed with the subjects of Lazar at Dubravnica, where they were successfully fought off. With a larger force, the Ottoman SultanMurad I attacked Serbia in 1386, when according to some sourcesNiš was conquered. Murad I had campaigned against the Karamanids and defeated their army near Konya. Serbian soldiers from some vassal Serbian lords had accompanied the Ottoman army. Some of the soldiers were executed because of looting civilian property, disobeying the Sultan's order. Many of the vassal Serbian lords now began to support Lazar against the Ottomans. At that time, one lord in Shkodër wrote a letter to the Sultan and promised to recognise Ottoman sovereignty and aid the Ottoman army if Ottoman troops were to be sent to protect him. Murad I thus ordered an akinji commander, Kula Şahin Bey, to prepare his troops.
Battle
The Serbian army emerged victorious, although details of the actual battle are vague. Şahin Bey entered Serbia with 20,000 akinjis at that time he learned that Serbian lords had prepared an army to attack his troops. He advanced to Pločnik near Prokuplje but could not detect the position of that army, and believed that there was none. At that time, many akinjis lost their temper and began looting civilian properties in the surrounding villages by disobeying orders. Şahin Bey stayed alone with 2,000 soldiers. On the other hand, the battlefield was observed by Serbian expeditionary forces. Suddenly an allied army with 15,000 soldiers appeared, many of whom were cavalry. The Serbian army used heavy knight cavalry charge with horse archers on the flanks. The Serbs first attacked the Ottoman center. Although unprepared, suffering a shock to heavy Serbian knights, the outnumbered Ottoman center resisted for some time but later began to withdraw with Şahin Bey who barely escaped with his life. Then the Serbian army turned to the other 18,000 akinjis that were busy plundering; unprepared, ill-disciplined, surprised akinjis couldn't do anything without their general. Only 5,000 of them returned home alive. More than 60% of the Ottoman army was destroyed. According to tradition Serbian knight and folk heroMiloš Obilić participated in this battle and distinguished himself, and was wounded by an Ottoman arrow. According to some, such as Croatian historian Vjekoslav Klaić, Lazar's army was aided by Bosnian troops. One version of the battle has it that the battle was won thanks to the Bosnian troops and the trickery of a Kastrioti.
Aftermath
The victory gave prestige to the Serbs and their rulers. It was the first serious defeat of the Ottomans in the Balkans. The Ottoman army next campaigned in Bosnia, fighting Bosnian troops led by Vlatko Vuković and Radič Sankovićat Bileća, ending in a decisive Bosnian victory, then in Kosovo, fighting Serbian troops at the Kosovo field, ending inconclusively. Murad had decided to make one more powerful thrust aimed at the heart of the now seemingly revitilisedSerbian Empire — Kosovo. Both Lazar and Murad fell in that battle.
