Miloš Obilić was a legendary Serbian knight who is reputed to have been in the service of Prince Lazar during the Ottoman invasion of Serbia in the late 14th century. He is not mentioned in contemporary sources, but features prominently in later accounts of the 1389 Battle of Kosovo as the assassin of Sultan Murad. Although the assassin remains anonymous in sources until the late 15th century, the dissemination of the story of Murad's assassination in Florentine, Serbian, Ottoman and Greek sources suggests that versions of it circulated widely across the Balkans within half a century of the event.

Lazar Hrebeljanović was a medieval Serbian ruler who created the largest and most powerful state on the territory of the disintegrated Serbian Empire. Lazar's state, referred to by historians as Moravian Serbia, comprised the basins of the Great Morava, West Morava, and South Morava rivers. Lazar ruled Moravian Serbia from 1373 until his death in 1389. He sought to resurrect the Serbian Empire and place himself at its helm, claiming to be the direct successor of the Nemanjić dynasty, which went extinct in 1371 after ruling over Serbia for two centuries. Lazar's programme had the full support of the Serbian Orthodox Church, but the Serbian nobility did not recognize him as their supreme ruler. He is often referred to as Tsar Lazar Hrebeljanović ; however, he only held the title of prince.