Simeon Uroš

Simeon Uroš, nicknamed Siniša (c. 1326–1370), was a son of King Stefan Dečanski of Serbia by the Byzantine princess Maria Palaiologina, and half-brother of Emperor Dušan. Dušan named him despot in 1346 and governor of Epirus and Acarnania in 1347; he won over the local aristocracy by marrying Thomais Orsini, daughter of the former ruler John II Orsini.

When Dušan died in 1355 and his son Stefan Uroš V took the throne, Simeon tried to make himself co-ruler and master of the empire's southern provinces. In 1356 he came into conflict with his nephew while trying to take Thessaly and Macedonia.

He then proclaimed himself emperor of the Serbs and Greeks and ruled a separate state centred on Thessaly and Epirus, splitting the south away from the empire, until his death in 1370. His son Jovan Uroš succeeded him.