In 924 Simeon determined on a supreme effort against Constantinople and as
a preliminary he ravaged Macedonia and Thrace. When, however, he arrived
before the city the walls and the catapults made him hesitate, and he
entered into negotiations, which, as usual, petered out and brought him no
adequate reward for all his hopes and preparations. In the west his arms
were more successful, and he subjected most of the eastern part of Serbia
to his rule. From all this it can be seen that he was no diplomat, though
not lacking in enterprise and ambition. The fact was that while he made
his kingdom too powerful for the Greeks to subdue (indeed they were
compelled to pay him tribute), yet Constantinople with its impregnable
walls, well-organized army, powerful fleet, and cunning and experienced
statesmen, was too hard a nut for him to crack.

Simeon extended the boundaries of his country considerably, and his
dominion included most of the interior of the Balkan peninsula south of
the Danube and east of the rivers Morava and Ibar in Serbia and of the
Drin in Albania. The Byzantine Church greatly increased its influence in
Bulgaria during his reign, and works of theology grew like mushrooms. This
was the only kind of literature that was ever popular in Bulgaria, and
although it is usual to throw contempt on the literary achievements of
Constantinople, we should know but little of Bulgaria were it not for the
Greek historians.

Simeon died in 927, and his son Peter, who succeeded him, was a lover of
peace and comfort; he married a Byzantine princess, and during his reign
(927-69) Greek influence grew ever stronger, in spite of several revolts
on the part of the Bulgar nobles, while the capital Preslav became a
miniature Constantinople. In 927 Rome recognized the kingdom and
patriarchate of Bulgaria, and Peter was duly crowned by the Papal legate.