Fall of the Serbian Empire Following the death of child - less Uroš the Weak , ( r . 1355 - 1371 ) the Serbian Empire was left without an heir and the military commanders obtained the rule of the past provinces and districts ( feudal fragmentation ) , continuing their offices with titles such as " gospodin " and " despot " etc . , given to them during the Empire . The nobility ( " velikaši " ) , were either subordinate to Emperor Uroš or his co - ruler ( as of 1366 ) Vukašin , thus the Empire may be viewed as a " de facto " diarchy ( 1366 – 1371 ) . Vukašin died in the Battle of Maritsa ( 1371 ) against the invading Ottoman Empire , which sought to conquer the whole of the Balkans . The southern provinces became nominal vassals . Four months later , Emperor Uroš died . The lords could not agree on the rightful ruler ; they dismissed Marko , the son of Vukašin , and within a year conflicts started between the nobles in plots and expansions of their provinces . An assembly was held in 1374 , without any success ; the nobles didn ' t agree on whether Marko or Duke Lazar would head the Serbian confederation , and Serbia continued as before , without a central authority . The period is known as the fall of the Serbian Empire . The initial years ( 1371 – 1389 ) are characterized by the emerging and fall of Duke Lazar Hrebeljanović ( initially a lord , later " autocrat " - as a suzerain ) , and the power struggle of the minor provinces . The rule of Lazar ends with the Battle of Kosovo on " Vidovdan " , June 15 , 1389 when Serbia stands up against the Ottomans , an event that is deeply rooted in Serbdom . Since the battle , and by 1395 , most of the southern imperial provinces are conquered and annexed by the Ottoman Empire , while the provinces of modern Central Serbia accepts nominal Ottoman rule . Lazar is succeeded by his son , Stefan , who later receives the title of " Despot " , hence Serbian Despotate - the Serbian state that existed 1402 - 1459 . The military commanders engaged in several conflicts ; civil wars , against , and with the Ottomans , the circumstances of which are richly attested in Serb epic poetry . Background . Uroš the Weak ' s rule . Dušan ' s son and heir Stephen Uroš V ( 1356 – 71 ) , though by this time twenty years old , was weak , possibly feeble - minded , and unable to take forceful action against his nobles ' separatist tendencies , hence his sobriquet " the Weak " , as opposed to his father Dušan , " the Mighty " . Dušan ' s half brother Simeon Uroš was expelled from Epirus and sought to obtain Serbia . He marched on Serbia in 1357 after he had himself proclaimed Tsar of the Greeks , Serbs , and Albanians at Kastoria in 1356 . The forces of Stephen Uroš met the forces of Simeon near Scutari in Zeta and forced them to back down . Meanwhile in the Serbian , Bulgarian and Byzantine borderlands of western Thrace , Matthew Kantakouzenos , the son of the Byzantine emperor John VI Kantakouzenos made war on the Serbs in 1356 - 57 but failed to capture Serres with his five - thousand Turks and was soon defeated in battle by Vojvoda Vojin and held for ransom . The ransom was paid by the Emperor John V Palaiologos and Matthew was allowed to retire to the Morea . Now the lands that remained loyal to Uroš were most of Macedonia , including the land between the Struma and Mesta rivers and the Chalcidice peninsula . The lands that remained Serbian could be divided into three main parts ; the western territories , including Zeta , the central Serbian lands of Uroš and the southern lands ( including the eastern part of Macedonia with Serres its capital ) . One of the strongest western nobles was Vojislav Vojinovic and he quarrelled with Dubrovnik in the fall of 1358 , when the Serbs and the Hungarians clashed along the Danube . The Hungarians penetrated deep into Serbian territory and the Serbian army retreated to avoid battle with the attackers . Vojislav waited until the Hungarians withdrew in 1359 then he attacked Dubrovnik . In 1363 the Hungarians and Wallachians were joined by Bosnian and Serbian forces committed to expel the Ottoman Turks from Europe . Caught by surprise near Adrianople , these forces were defeated by the Turks in 1364 on the banks of the Maritsa river . In 1365 Vukashin was proclaimed King of Serbia and co - ruler with Uroš and Jovan Uglješa was made Despot in the Serbian principality of Serres . History . Battle of Maritsa . There was a far more serious problem for Serbia - and the whole Balkans - than the internal squabblings of the Serbian Nobles and that was the appearance in Europe of the Ottoman Turks . Followed by their penetration into Thrace , in 1354 they acquired Gallipoli on the European side of the Dardanelles . From there they , or Turkish bands loyal to them expanded into Thrace , taking Demotika from the Byzantines in 1361 and Philippopolis from the Bulgarians in 1363 and finally in 1369 the major city of Adrianople . By 1370 Turks had occupied most of Thrace to the Rhodopes and to the Balkan Mountains . As they reached the Rhodopes they collided with Jovan Ugljesa who had extended his realm beyond the Mesta into this territory and the threat from them became increasingly serious . On September 26 , 1371 , " King " Vukašin Mrnjavčević with his brother " Despot " Jovan Uglješa led the Serb Army against the advancing Ottoman Empire led by the beylerbey of Rumeli Lala Şâhin Paşa at Maritsa . The offensive against the Turks was originally scheduled for early 1371 , but was delayed perhaps because Uglješa had hoped that Bulgaria might also join the coalition . King Vukašin and his son Marko were in Skadar preparing for action against Nicholas Altomanovich when they were summoned east to join up with Uglješa and his army and then together they easily penetrated into what was supposedly Turkish territory and reached Cernomen on the Maritza River , where the Serbs ( who thought themselves invincible ) did not bother to post sentries or have scouts as did the Turks . Furthermore they did not keep their horses or their weapons in readiness and they allowed themselves to be surprised . The Ottomans won the battle , as they attacked the Serbian army while they rested . The bodies of the commanders were not found . Prince Marko inherited the title of his father , and became the co - ruler of Emperor Uroš . Death of the Emperor . Stefan Uroš V died childless in December 2 / 4 1371 , after much of the Serbian nobility had been destroyed by the Turks in the Battle of Maritsa earlier that year . Vukašin ' s son Marko inherited his father ' s royal title , and thus became the disputed successor of the Serbian throne , the nobles pursued their own interests , quarreling with each other . Real power in northern Serbia was held by Lazar Hrebeljanović . The latter did not assume the imperial or royal titles ( associated with the Nemanjići ) , and in 1377 accepted king Tvrtko I of Bosnia ( a maternal grandson of Stefan Dragutin ) as titular king of Serbia . Serbia proper became a vassal of the Ottomans in 1390 but remained effectively ruled by the Lazarević s and then by their Branković s successors until the fall of Smederevo in 1459 . Đurađ II Balšić edict . In 1372 Đurađ had succeeded his father Stracimir as the lord of Upper Zeta . Đurađ , in the standards of collective family reign , issued together with his uncles Balša II and presiding Đurađ I an edict in the Republic of Ragusa on 30 November 1373 . The edict confirmed the laws of Emperor Stefan Uroš from the Serbian Nemanjić and gave privileges to Ragusian traders , including imposed taxes to the Adriatic City . It also included a unique clause , recognizing the sovereignty and territorial integrity of the Serbian Empire even though for years without an Emperor and any form of centralized strong authority , a note that if anyone would became the new sovereign Emperor of the Serbs and the Serbian nobility and lands , all the points shall be transferred from the Balšićs to him . Đurađ I ' s " logotet " Vitko was the witness , as well as Dragaš Kosačić . The collectivity of the family of the Balšićs marked this unique feudal system applied to their domain . Plots against Marko . When his father died , " young king " Marko legally became a king and the co - ruler of Tsar Uroš . Soon afterwards came the end of the Nemanjić dynasty , when Uroš died on 2 or 4 December 1371 , which formally made Marko the sovereign of the Serbian state . Serbian lords , however , did not even consider to recognize him as their supreme ruler , and the separatism within the state increased even more . After the demise of the two brothers and the destruction of their armies , the House of Mrnjavčević was left without any real power . Lords surrounding Marko took the opportunity and seized significant parts of his patrimony . By 1372 , Đurađ I Balšić grabbed Prizren and Peć , and Prince Lazar Hrebeljanović took Priština . By 1377 Vuk Branković acquired Skopje , and Albanian magnate Andrija Gropa became practically independent in Ohrid . The latter possibly remained a vassal to Marko as he had been to Vukašin . Gropa ' s son - in - law was Marko ' s relative Ostoja Rajaković of the clan of Ugarčić from Travunia . He was one of the Serbian nobles from Zachlumia and Travunia ( adjacent principalities in present - day Herzegovina ) who had received lands in the newly conquered parts of Macedonia during Tsar Dušan ' s reign . After the Battle of Maritsa , Marko , the son of Vukašin Mrnjavčević , was crowned king and gained his father ' s lands . However , his friendship with the Balšićs soon crumbled . This was a result of Đurađ , in 1371 , expelling his first wife Olivera , Marko ' s sister , and took Prizren from Marko . Lazar Hrebeljanović , prince of Moravian Serbia , conquered Priština in the same year . Đurađ took Peć a year later , stripping most of Marko ' s lands north of Šar mountain . Plot against Nikola . In the spring of 1371 , Marko participated in the preparations for a campaign against Nikola Altomanović , the major lord in the west of the Empire . The campaign was planned jointly by King Vukašin and Đurađ I Balšić , the lord of Zeta , who was married to Olivera , the king ' s daughter . In July that year , Vukašin and Marko camped with their army outside Scutari , on Balšić ' s territory , ready to make an incursion towards Onogošt in Altomanović ' s land . The attack never happened , as the Ottomans threatened the land of Despot Jovan Uglješa , the lord of Serres , Vukašin ' s younger brother who ruled in eastern Macedonia . The forces of the Mrnjavčevićs were quickly directed eastward . Having in vain looked for allies , the two brothers finally entered with their own troops into the territory controlled by the Ottomans . At the Battle of Maritsa on 26 September 1371 , the Turks annihilated the Serbian army ; not even the bodies of Vukašin and Jovan Uglješa were ever found . The place where it was fought , near the village of Ormenio in the east of present - day Greece , has ever since been called " Sırp Sındığı " " Serbian Rout " in Turkish . The outcome of this battle had serious consequences — it actually opened up the Balkans to the Turks . In 1371 , Đurađ announced to Ragusan Republic that Vukašin Mrnjavčević and his son , Marko , along with their armies , were in Scutari with Đurađ , preparing an attack on Altomanović . Dubrovnik assisted their campaign by providing ships to transport men and supplies , since their campaign was in Dubrovnik ' s interests . However , the campaign never took place as Vukašin and Marko went to aid Vukašin ' s brother , Jovan Uglješa , in a campaign against the Turks , which ended up in total disaster , Uglješa being killed in the Battle of Maritsa . Altomanović though was now in even more trouble . Prince Lazar Hrebeljanović of Serbia and Ban Tvrtko I of Bosnia allied themselves to defeat Nikola Altomanović . Desperate for a strong ally , Altomanović began negotiations with Đurađ . Most historians agree that in concluding negotiations , Đurađ gained the towns of Trebinje , Konavle and Dračevica from Altomanović , possibly a bribe to remain neutral within the war . Other historians , however , follow Mauro Orbini ' s account and argue that Đurađ never concluded such an agreement , rather conquered the towns he gained from the agreement himself after Altomanović was defeated in 1373 . Sabor 1374 . The Sabor took place on September 26 , 1374 , symbolically three years since the Battle at Maritsa . The Sabor was held to stop the discord between Serbian nobles . Marko and Lazar both claimed the titles of King , with Vuk Brankovic supporting Lazar . Crowning of Tvrtko . On 26 October 1377 , Tvrtko had himself crowned as Stephen Tvrtko I , " by the Grace of God , King of the Serbs , Bosnia and the Seaside and the Western Lands " . Today , some historians consider that he was crowned in Monastery of Mileševa , even though there is no evidence of that . Another possibility , supported by archaeological evidences , is that he was crowned in Mile near Visoko in the church which was built in time of Stephen II Kotromanić ' s reign , where he was also buried alongside his uncle Stjepan II . Stephen ( " Stefan " ) was the standard title of the rulers of the Nemanjić dynasty . In 1375 – 1377 Tvrtko created a unique genealogy that explicitly stated his descendency from the Nemanjići . Death of Balšić . Đurađ I died on 13 January 1378 in Skadar . However , recent studies now conclude that Đurađ died in 1379 rather than in 1378 . The rule of Zeta was passed down to his younger brother , Balša II . Đurađ ' s death caused quite a stir between Zeta ' s neighbours . Bosnian Ban Tvrtko I annexed Đurađ ' s territories bordering Dubrovnik in 1377 , along with the remainder of Đurađ ' s coastal lands between the Bay of Kotor and the land previously annexed in 1377 at the time of his death . Tvrtko secured these possessions through Đurađ ' s death , free of worry of any counter - attack . Vuk Branković also took this opportunity to gain Đurađ ' s land . Branković sent his forces into Metohija and seized Prizren , along with the rest of Đurađ ' s holdings in the region . Rise of Lazar . By 1379 , Prince Lazar Hrebeljanovic , the lord of Pomoravlje , emerged as the first and most powerful among Serbian nobles . In his signatures , he titled himself as the Autokrator of all the Serbs ( ) ; nevertheless , he was not powerful enough to unite all Serbian lands under his authority . The Houses of Balšić and Mrnjavčević , Konstantin Dragaš ( maternally a Nemanjić ) , Vuk Branković , and Radoslav Hlapen , ruled in their respective domains without consulting with Lazar . Another king besides Marko advanced on the political scene : in 1377 , the Metropolitan of Mileševa crowned Tvrtko I , maternally related to the Nemanjići , " King of the Serbs and of Bosnia " . He had previously taken some western parts of the former Serbian Empire . After taking Nikola Altomanovic ' s lands in 1379 , he subordinates Radic Sankovic . Battle of Kosovo . On 28 June 1389 , Serbian forces led by Prince Lazar , Vuk Branković , and Tvrtko ' s nobleman Vlatko Vuković of Zachlumia , confronted the Ottoman army led by Sultan Murad I and his two sons Bayezid and Yakub . This was the Battle of Kosovo — the most famous battle in Serbia ’ s medieval history . The majority of the Serbian army was obliterated in battle ; Vuk Brankovic who led the Serbian right wing routed the left wing of the Ottomans being led by another son of Murad - Yakub after the Serbian heavy cavalry smashed into the Ottoman left and damaged the Ottoman center pushing them back and gaining the first advantage . Bayezid the other son of Murad commanded the Ottoman right which was made up of four Turkish , two Serbian and one Bulgarian division and he held off the forces of Vlatko Vukovic ( who smashed the Turks at Bileca and was now inflicting severe casualties on Bayezids frontline troops ) commanding the Serbian / Bosnian army on the left of the main body of Serbians under Prince Lazar . Bayezid , with his reserves fresh and ready for battle counterattacked the Serbs under Lazar who had been pushing hard against the Ottoman center and broke through all the way to where the wounded Prince Lazar was being sheltered and captured the Serbian Prince bringing him and other Serbian nobles before the dying body of Murad who had been stabbed and mortally wounded by the Serb Milos Obilic who pretended to be a deserter and while he died Lazar was beheaded along with the flower of the Serbian aristocricy . The Serbs that remained alive retreated and then the Ottomans also withdrew after they lost so many of their soldiers ( killed and wounded ) that they could not continue their campaign but equally important was the fact that Bayezid who was to succeed his father Murad and had conveniently had Yakub strangled had to retreat to Adrianople in order to be proclaimed the new Ottoman Sultan . The battle was clearly a loss for the Serbian prince and his vassals , and in the wake of it the Serbs were left with too few men to effectively defend their lands , while the Turks had many more troops in the east . Consequently , the Serbian principalities that were not already Ottoman vassals , one after the other became so in the following years . The majority of the Serbian army was obliterated in battle ; but both Lazar and Murad lost their lives in it , and the remnants of their armies eventually retreated from the battlefield . Furthermore , in response to Turkish pressure , some Serbian noblemen wed their daughters , including the daughter of Prince Lazar , to Bayezid . In the wake of these marriages , Stefan Lazarević became a loyal ally of Bayezid , going on to contribute significant forces to many of Bayezid ' s future military engagements , including the Battle of Nicopolis . Eventually , the Serbian Despotate would , on numerous occasions , attempt to defeat the Ottomans in conjunction with the Hungarians until its final defeat in 1459 and again in 1540 .