Simeon Uroš (Serbian Cyrillic: Симеон Урош, Greek: Συμεών Ούρεσης; c. 1326–1370), nicknamed Siniša (Синиша), was the Emperor of Epirus from 1359 to 1366, and of Thessaly from 1359 until his death in 1370. He initially governed Epirus and Acarnania under his half-brother Emperor Stefan Dušan (r. 1331–55) from 1348 until Dušan's death in 1355, when Simeon ruled these regions as self-proclaimed Emperor of the Serbs and Greeks in rivalry with his nephew Stefan Uroš V.
Simeon in his younger years, Visoki Dečani.
Simeon Uroš was the son of King Stefan Dečanski (r. 1322–31) by his second wife, Maria Palaiologina, the daughter of the Byzantine prince and rebel John Palaiologos who had joined Dečanski's raids in Macedonia in 1326, the same year Simeon Uroš was born. His older, half-brother, Dušan was crowned "Young king" (designated heir) in 1322 during the crowning of their father.
Stefan Dušan's reign
Stefan Dušan was crowned King in September 1331, after months of civil war. Dušan exploited the Byzantine civil war and made major gains beginning in 1342. Having all of Macedonia under his rule, Stefan Dušan was proclaimed "Emperor of Serbs and Greeks" in September 1345, then crowned as such in April 1346. Dušan, as an emperor, granted Byzantine titles upon his magnates. Simeon Uroš and Jovan Asen were given the despot title, while others were given the sebastokrator and kesar titles.
With the Serbian conquest of Epirus, Acarnania and Thessaly by 1348, Simeon Uroš was given the governorship of Epirus and Thessaly. Simeon Uroš consolidated his position with the local aristocracy by marrying Thomais Orsini, the daughter of the former ruler of Epirus, John II Orsini.
Claim to the Serbian throne and independence
Simeon Uroš's relatively uneventful governorship was interrupted when, shortly after Dušan's death in 1355, his brother-in-law Nikephoros II Orsini, the deposed ruler of Epirus, reappeared in Greece and gained the support of the nobility in Thessaly and Epirus. In 1356 Nikephoros entered Epirus and forced Simeon Uroš to flee to Kastoria. There Simeon proclaimed himself "Emperor of Serbs and Greeks" in rivalry with his nephew Stefan Uroš V.
Although he was supported by some important magnates like Jovan (the brother of Stefan Dušan's widow), Simeon was rejected by the nobility of the Serbian lands and Macedonia. After he was forced to retreat from his attempt to invade Zeta (modern Montenegro) in 1358, Simeon Uroš gave up hope of asserting himself in Serbia. The next year, however, Nikephoros II Orsini was killed in a skirmish against Albanian clans, opening an opportunity for Simeon Uroš. Consequently, he rapidly swept into Thessaly and was acknowledged as its ruler in 1359. He then invaded Epirus, where the towns, harried by the Albanian clans who had taken over the countryside, also recognized his authority. He also used his maternal maiden name, Palaiologos (Παλαιολόγος), during his rule.
While Simeon Uroš was in Epirus, Radoslav Hlapen of Vodena (Edessa) attempted to seize Thessaly on behalf of his stepson Thomas Preljubović. Simeon Uroš was forced to cut his losses by recognizing Radoslav Hlapen's conquests, turning over Kastoria to him, and marrying his daughter Maria to Thomas. Hlapen recognized Simeon Uroš's suzerainty in at least some of these lands and provided a buffer between him and the Serbian nobles to the north. Simeon Uroš established himself in Trikala in Thessaly, and spent the remaining decade of his reign in relative peace. He soon recognized two of the Albanian leaders in Epirus, John Spata and Peter Losha, as despotes of Arta and Angelokastron. In 1366 he turned over Ioannina, his last major possession in Epirus, to his son-in-law Thomas, who ruled there as a vassal despot.
In Trikkala, Simeon Uroš presided over a court including Byzantine, Serbian, and Albanian nobles, but he showed preference for the Byzantine relatives of his wife. He also founded and generously endowed the monasteries of Meteora. He died in 1370.