Tsar Simeon I the Great 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 and Southeast Europe. His reign was also a period of unmatched cultural prosperity and enlightenment later deemed the Golden Age of Bulgarian culture.

Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. Located west of the Black Sea and south of the Danube river, Bulgaria is bordered by Greece and Turkey to the south, Serbia and North Macedonia to the west, and Romania to the north. It covers a territory of 110,994 square kilometres (42,855 sq mi) and is the 16th largest country in Europe. Sofia is the nation's capital and largest city; other major cities include Burgas, Plovdiv, and Varna.