The son of Prince Lazar Hrebeljanović, he was regarded as one of the finest knights and military leaders at that time. After the death of his father at Kosovo (1389), he became ruler of Moravian Serbia and ruled with his mother Milica (a Nemanjić), until he reached adulthood in 1393. Stefan led troops in several battles as an Ottoman vassal, until asserting independence after receiving the title of despot from the Byzantines in 1402.