Claim: Jovan Oliver was a noble with several titles under the Serbian Emperor Dušan the Mighty, who was Serbia's King.
Evidence: Jovan Oliver Grčinić (Serbian: Јован Оливер Грчинић; ca. 1310-1356) was a magnate of the Serbian Emperor Dušan the Mighty (r. 1331-1355), holding the titles of sebastokrator and despotes, and the rank of "great voivode", showing his prominence and status as one of the most important nobles of Dušan. Stefan Uroš IV Dušan (Serbian Cyrillic: Стефан Урош IV Душан, pronounced [stêfaːn ûroʃ tʃětʋr̩ːtiː dǔʃan (listen)), known as Dušan the Mighty (Serbian: Душан Силни / Dušan Silni; circa 1308 – 20 December 1355), was the King of Serbia from 8 September 1331 and Tsar (or Emperor) and autocrat of the Serbs and Greeks (or Romans) from 16 April 1346 until his death.