Stefan Lazarević
When Timur's army entered the Ottoman realm, Stefan Lazarević participated in the Battle of Ankara in 1402, in which the Ottomans were defeated and their leader Bayezid was captured. Returning to Serbia, Stefan visited Constantinople where the Byzantine emperor Manuel II Palaiologos granted him the title of despot. In previous years, this title would mean that the despot would rule some vassal state; however, as the Byzantine Empire was too weak to assert such a rule and Serbia was not its vassal state, Stefan Lazarević took this title as the personal style of the Serbian monarchs.