Stefan Uroš V

Saint Stefan Uroš V (Serbian Cyrillic: Стефан Урош V, pronounced [stêfaːn ûroʃ peːti] ; 1336 – 2/4 December 1371), known in historiography and folk tradition as Uroš the Weak (Serbian: Урош Нејаки, romanized: Uroš Nejaki), was the second Emperor (Tsar) of the Serbian Empire (1355–1371), and before that he was Serbian King and co-ruler (since 1346) with his father, Emperor Stefan Dušan.

Source: Wikipedia — https://en.wikipedia.org/wiki/Stefan_Uro%C5%A1_V