Stefan Uroš IV Dušan (Serbian Cyrillic: Стефан Урош IV Душан, pronounced [stêfaːn ûroʃ tʃětʋr̩ːtiː dǔʃan]), known as Stefan Dušan, the Mighty (silni/силни; c. 1308 – 20 December 1355), was the King of Serbia from 8 September 1331 and Emperor of the Serbs and Greeks from 16 April 1346 until his death. Dušan conquered a large part of southeast Europe, becoming one of the most powerful monarchs of the era. He enacted the constitution of the Serbian Empire, known as Dušan's Code, perhaps the most important literary work of medieval Serbia.

Dušan promoted the Serbian Church from an archbishopric to a Patriarchate, finished the construction of the Visoki Dečani monastery (a UNESCO site), and founded the Saint Archangels Monastery, among others. Under his rule Serbia reached its territorial, political, economic, and cultural peak.

Dušan died in 1355, seen as the end of resistance against the advancing Ottoman Empire and the subsequent fall of the Eastern Orthodox Church in the region. His wars with the Byzantine Empire caused the later to ask the Turks for assistance. In the process the Turks gained a foothold on European land at Gallipoli.

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