Stefan Lazarević was born, probably, in 1377 in Kruševac, the capital of his father, Prince Lazar. After the Battle of Kosovo on 15 June 1389, where his father was killed, Stefan became the new Serbian prince, but before he became of age the state was ruled by his mother, Princess Milica. In the battle of Kosovo in 1389, both rulers were killed, the Serbian Prince Lazar and Ottoman Sultan Murad I, which is very rare in history. (Murad I was the first and the last Ottoman ruler who was killed on the battlefield).