Inadequate ruling was ultimately the reason for the fall of Serbian Empire. Stefan Uroš IV Dušan, also known as Dušan the Mighty, was a great Serbian king who ruled firmly and justly over the empire. But upon his death, Stefan V came to power and he was a complete opposite of the great father. His weak personality and total ignorance of anything concerning the country led to the fall of the empire within mere years. Then he became the last known emperor of Serbia.