The battle, in which both Lazar and Murad died, was crucial to Serbia's passage into vassaldom of the encroaching Ottoman Empire in the Balkans. In modern times, however, a Serbian national myth was established with the event, which was perceived as a defeat, the blackbird field or Kosovo myth. Although the battle ended without a clear winner, as leaders of both armed forces fell, the result was that the resistance of the Serbian princes against a military or numerically superior opponent was broken for the time being.[5] They therefore had to recognize the suzerainty of the Ottoman sultans, which made the remaining Serbian principality obligated to pay tribute, although Vuk Branković and Đurađ Branković in particular resisted for a long time after the battle. This battle was later glorified as the national myth of the Serbs. In 1459, Serbia was finally conquered by the Ottomans and remained part of the Ottoman Empire until 1804.
The tower has an inscription on the base that originated from the so-called Kosovo myth. According to legend, it is the "Kosovo Oath" written by Prince Lazar from a folk song by Vuk Stefanović Karadžić. This "oath" for the coming battles consists almost entirely of curses against treachery, aimed at those who would not take part in the battle. The traitors are condemned to be without posterity, outcasts for all time. The oath appears as an incantation to ward off treason with a curse threat. Most of the songs related to the so-called Kosovo myth were written down during the 19th century, the era of European nationalism, which explains why traces of a transition to nationalism can already be found in some of them. Loyalty to the prince and faith are no longer given as the reason for going into battle in Kosovo, but rather an obligation to Serbian ancestors, Serbian blood and Serbian education, which form the basis for the oath made to Lazar. It was only in Karadžić's songs that Lazar's choice between an honorable death and a life of shame changed to the choice we know today between the "earthly and heavenly kingdoms". The accent of the oath in the Kosovo myth shifted further from the religious to the political, because the sacrificing hero is not only promised fame and eternal life. Eternal continuity is also promised for the kingdom, which is the point of reference for national aspirations.
Source: Wikipedia