Prince Lazar Hrebeljanović (ca.

1329 – 15 June 1389) is a medieval Serbian ruler, who creates the largest and most powerful state on the territory of the disintegrated Serbian Empire.

Lazar's state, known in historiography as Moravian Serbia, comprises the basins of the Great Morava, West Morava, and South Morava Rivers.

Lazar rules it from 1373 until his death in 1389.

Lazar's political program is the reunification of the disintegrated Serbian state under him as the direct successor of the Nemanjić dynasty, which had ended in 1371 after two centuries of rule over Serbia.

Lazar ha full support from the Serbian Church for this program, but powerful Serbian nobles do not recognize him as their supreme ruler.

In the Battle of Kosovo fought on June 15, 1389, Lazar leads the army that confronts a massive invading army of the Ottoman Empire commanded by Sultan Murad I.

Both Prince Lazar and Sultan Murad lose their lives in the battle.

Although the battle is tactically inconclusive, the mutual heavy losses are devastating only for the Serbs.

Lazar's widow, Milica, who rules as regent for her minor son Stefan Lazarević, Lazar's successor, accepts Ottoman suzerainty in the summer of 1390.

Lazar is venerated in the Serbian Orthodox Church as a martyr and saint, and is highly regarded in Serbian history, culture and tradition of the Serbs.

In Serbian epic poetry he is called Tsar Lazar.