High Quality Content by WIKIPEDIA articles! Simeon (also Symeon)I the Great (Bulgarian: Симеон I Велики, transliterated Simeon I Veliki) ruled over Bulgaria from 893 to 927, during the First Bulgarian Empire. Simeon`s successful campaigns against the Byzantines, Magyars and Serbs led Bulgaria to its greatest territorial expansion ever, making it the most powerful state in contemporary Eastern Europe. His reign was also a period of unmatched cultural prosperity and enlightenment later deemed the Golden Age of Bulgarian culture.