Editing Battle of Kosovo (section)

===Geopolitical consequences===
Both armies were destroyed in the battle.<ref name="Fine-1994-409-11">{{harvnb|Fine|1994|pp=409–411}}</ref> Both Lazar and Murad lost their lives, and the remnants of their armies retreated from the battlefield. Murad's son [[Bayezid I|Bayezid]] killed his younger brother, Yakub Çelebi, upon hearing of their father's death, thus becoming the sole heir to the Ottoman throne.<ref>{{Cite book |last=Imber |first=Colin |title=The Ottoman Empire, 1300-1650: the structure of power |publisher=Palgrave Macmillan |year=2009 |isbn=978-0-230-57451-9 |location=Basingstoke, NY |page=85}}</ref> The Serbs were left with too few men to defend their lands effectively, while the Turks had many more troops in the east.<ref name=Fine-1994-409-11/> The immediate effect of the depletion of Serbian manpower was a shift in the stance of Hungarian policy towards Serbia. Hungary tried to exploit the effects of battle and expand in northern Serbia, while the Ottomans renewed their campaign in southern Serbia as early as 1390–1391. Domestically, the Serbian feudal class in response to these threats split in two factions. A northern faction supported a conciliatory, pro-Ottoman foreign policy as a means of defence of their lands against Hungary, while a southern faction which was immediately threatened by Ottoman expansion sought to establish a pro-Hungarian foreign policy. Some Serbian feudal lords continued to fight against the Ottomans and others were integrated in the Ottoman feudal hierarchy. Consequently, some of the Serbian principalities that were not already Ottoman vassals became so in the following years.<ref name=Fine-1994-409-11/> These feudal lords{{snd}}including the daughter of Prince Lazar{{snd}}formed marriage ties with the new Sultan Bayezid.<ref>{{Cite book |last=Volkan |first=Vamik D. |url=https://books.google.com/books?id=iQbZL9IycwMC |title=Bloodlines: From Ethnic Pride to Ethnic Terrorism |publisher=Westview |year=1998 |isbn=978-0-8133-9038-3 |page=61}}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{Cite book |last=Quataert |first=Donald |url=https://books.google.com/books?id=OX3lsOrXJGcC |title=The Ottoman Empire, 1700-1922 |date=11 August 2005 |publisher=Cambridge University Press |isbn=978-0-521-83910-5 |page=26}}</ref><ref>{{Cite book |last=Shaw |first=Stanford J. |title=History of the Ottoman Empire and Modern Turkey. 1: Empire of the Gazis: the rise and decline of the Ottoman Empire, 1280–1808 |publisher=Cambridge University Press |year=2002 |isbn=978-0-521-29163-7 |page=24}}
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In the wake of these marriages, [[Stefan Lazarević]], Lazar's son, became a loyal ally of Bayezid, and contributed significant forces to many of Bayezid's future military engagements, including the [[Battle of Nicopolis]], where [[Vuk Branković]] another Serbian magnate who ruled in parts of Kosovo had joined the anti-Ottoman coalition. As a reward for his contribution to the Ottoman victory, Lazarević was given a large part of Branković's lands. Branković himself died as an Ottoman prisoner, although in all later "Kosovo myth" narratives first created by Stefan Lazarević, he is portrayed as a betrayer of the Christians. Lazarević's success as an Ottoman vassal was such that eventually his lands encompassed a territory bigger than his father's and matched the territories of the Nemanjic dynasty in the 13th century.{{sfn|Djokić|2023|p=131|ps=:In terms of political and economic significance and its territorial extent, the Lazarević-Branković despotate matched the thirteenth-century Nemanjić kingdom.}} After [[Mehmed I|Mehmed]]'s death in 1421, Lazarević was one of the vassals who strongly supported the coalition against the future [[Mehmed II|Mehmed the Conqueror]] who ultimately prevailed. This move led Mehmed to punish the Serbian and all other vassals who supported the other claimants to the throne by campaigning against them to directly annex their lands. In a series of campaigns from this era onward Serbia formally became an Ottoman province.{{sfn|Djokić|2023|p=132}} The capture of [[Smederevo Fortress|Smederevo]] on June 20, 1459 marks the end of medieval Serbian statehood.{{sfn|Fine|1994|p=575}}