Mileva Olivera Lazarevi, Despina Hatun was the youngest daughter of Lazar of Serbia and Princess Milica and the wife of Ottoman Sultan Bayezid I, whom she married just after the Battle of Kosovo in 1389, as a pledge of peace between the Lazarevi and Ottoman dynasties. After the marriage, she became Despina Hatun .
Olivera Despina Hatun was born around 1372, the youngest daughter of Prince Lazar and Princess Milica of Serbia. Her mother was a descendant of Grand Prince Stefan Nemanja, the founder of the Nemanji dynasty and the fourth cousin once removed of Emperor Duan of Serbia. Olivera had four older sisters, Mara , Dragana, Teodora, and Jelena and two brothers, Serbian despot Stefan Lazarevi and Vuk. After the Battle of Kosovo in 1389, Olivera was sent to the harem of sultan Bayezid I, where she remained for the nextyears and became one of sultans four wives . Despite her marriage, she never converted to Islam. She had a great influence on the sultan, which helped her people, country, and family survive the turbulent times.
Source: Wikipedia