| Jovan Uglješa | |
| Birth Name: | Jovan Uglješa Mrnjavčević |
| Death Date: | 26 September 1371 |
| Death Place: | Maritsa |
| Death Cause: | Killed in action |
| Grand Voivode (Veliki Vojvoda) Despot | |
| Spouse: | Jelena (Jefimija) |
| Parents: | Mrnjava |
Jovan Uglješa Mrnjavčević (Serbian: Јован Угљеша Мрњавчевић; fl. 1346–1371), known as Jovan Uglješa (Serbian: Јован Угљеша), was a Serbian medieval nobleman of the Mrnjavčević family and one of the most prominent magnates of the Serbian Empire. He held the title of despot, received from Serbian Emperor Stefan Uroš V, whose co-ruler - Serbian King Vukašin was Uglješa's brother.
Uglješa was the son of Mrnjava, a treasurer of Helen of Anjou, the queen consort of Stephen Uroš I of Serbia. He held Travunia in 1346, during the rule of Stefan Dušan (1331–1355).[1]
Uglješa married Jelena (later nun Jefimija), daughter of Vojihna, the Caesar of Drama.[2] This boosted the power of Uglješa, who would later govern the region alongside his father-in-law.[2] Vojihna died in ca 1360, and his lands were inherited by Uglješa.
He was given the title of despotes by Empress Helena of Bulgaria in 1365. His province was situated along the lower course of the Struma with Serres as seat. His realm was under the religious jurisdiction of the Ecumenical Patriarchate of Constantinople since 1368. The Patriarch mentioned the master of Raška (another name for Serbia), Jovan Uglješa, in a letter from 1371.
With the Ottoman threat rising in the Balkans, Ugleša and his brothers Vukašin Mrnjavčević and Gojko Mrnjavčević tried to oppose the Turks. Uglješa was killed on 26 September 1371 in the Battle of Maritsa. Their troops were smashed by those of Ottoman commanders Lala Shahin Pasha and Gazi Evrenos at the Battle of Maritsa in 1371. The defeat resulted in big portions of the region of Macedonia falling under Ottoman power. Additionally, two brothers were killed during the fight. Their courage made them heroes of Bulgarian and Serbian epic poetry.
. Sima Ćirković. 2004. The Serbs. Malden. Blackwell Publishing. 9781405142915.
. Francis Dvornik. The Slavs in European History and Civilization. 1962. New Brunswick, New Jersey. Rutgers University Press. registration.
. Donald M. Nicol. The Reluctant Emperor: A Biography of John Cantacuzene, Byzantine Emperor and Monk, c. 1295-1383. 1996. Cambridge. Cambridge University Press. 9780521522014.
. George Ostrogorsky. History of the Byzantine State. 1956. Oxford. Basil Blackwell.