The Serbian Empire (Српско царство / Srpsko carstvo, sr̩̂pskoː tsâːrstʋo) was a medieval Serbian state that emerged from the Kingdom of Serbia. It was established in 1346 by Dušan the Mighty, who significantly expanded the state.
During Dušan's rule, Serbia was the most powerful state in Southeast Europe and one of the most powerful European states. It was an Eastern Orthodox multi-ethnic and multi-lingual empire that stretched from the Danube in the north to the Gulf of Corinth in the south, with its capital in Skopje. He also promoted the Serbian Archbishopric to the Serbian Patriarchate. His son and successor, Uroš the Weak, lost most of the territory conquered by Dušan, hence his epithet.
The Serbian Empire effectively ended with the death of Uroš V in 1371 and the break-up of the Serbian state. Some successors of Stefan V claimed the title of Emperor in parts of Serbia until 1402, but the territory in Greece was never recovered.
Byzantine civil war of 1341–1347 and Stefan Dušan
Stefan Dušan was the son of the Serbian king Stefan Dečanski (r. 1322–1331). After his father's accession to the throne, Dušan was awarded with the title of "young king". Although this title bore significant power in medieval Serbia, Stefan wanted his younger son, Simeon Uroš, to inherit him instead of Dušan. However, Dušan had significant support from the major part of the Serbian nobility, including the Serbian archbishop Danilo, and some of the king's most trusted generals, such as Jovan Oliver Grčinić. Tensions slowly rose between the king and his son, especially after the battle of Velbužd, where Dušan showed his military capabilities, and they seem to have culminated when king Stefan raided Zeta, a province in Serbia where Dušan ruled autonomously, being a tradition of Serbian heirs to rule this province. Advised by the nobility, Dušan later marched from Zeta to Nerodimlje, where he besieged his father and forced him to surrender the throne. Stefan was later imprisoned in the fortress of Zvečan, where he died.