Simeon (893-927), the third son of Boris I, who came to replace his overthroned brother, received a rich legacy from his father, a legacy that gave uncountable fruit during his long reign, but - unlike most great people's descendants - he did not remain in his parent's shadow.
Graduate of the brilliant Magnaur school in Constantinople, writer, philosopher and scholar, he was the favorite of both the muses and the bellicose Mars. Under his rule the Bulgarian state acquired its ever largest territory, and, more than once, his campaigns southward critically endangered the Byzantine Empire. In a unique letter, one of his, as a whole, abundant diplomatic correspondence with Constantinople, is a telling example of the balance of power at that time - in reply to the tortuous rhetoric of the patriarch Nicholas Mysticon, who had tried to appease him, Simeon answered in one single sentence: "You have grown weak in the head."
In the time of Simeon the princely (khan's) title of the Bulgarian sovereigns "skipped" the regal one to become a tzar's, i.e. emperor's (half a millennium later Ivan the Terrible would be able to achieve the same in Moscow), and the Bulgarian archbishopric was raised to the rank of patriarchate.
The abundant tax returns and wartime spoils received by the treasury, made it possible to begin a large-scale construction of towns, fortresses, magnificent palaces and temples. The cultural bloom, whose seeds had been thrown in the time of Boris, reached its apogee - Bulgaria under Simeon entered its Golden Age. The cataclysms brought about by the later ages account for the circumstance that the huge amount of literature, written under Simeon's patronship, has survived till the present day very often only in Russian, Serbian, Roumanian, etc. copies, but this fact speaks for itself too.
Simeon, like Kroum, died of a heart attack while preparing his next campaign against Constantinople.
Special Thanks to Wonderland Bulgaria