244 Darwinism and Other Essays. 



These eastern conquests were not long retained, 

 but on the other hand the semi-independent king- 

 dom between the Danube and the Balkan Moun- 

 tains became more and more formidable in its 

 rivalry with the imperial government at Constan- 

 tinople. In long and obstinate warfare the Bul- 

 garians overcame the Serbs, and by the beginning 

 of the tenth century they controlled nearly the 

 whole peninsula from the Black Sea to the Adri- 

 atic. At this epoch their kingdom was perhaps 

 as civilized as any in contemporary Europe, if 

 literary culture alone were to be taken as a cri- 

 terion. Their noble youth studied Aristotle and 

 Demosthenes in the schools of Constantinople, 

 and the subtleties of theological controversy occu- 

 pied their attention no less than the practice of 

 military arts. In a quarrel with the emperor, 

 their Czar Simeon laid siege to the capital and 

 dictated terms of peace at the Golden Horn. But 

 in the next century all this was changed. Such 

 arrogant vassals were not to be tolerated. In a 

 masterly campaign, though sullied by diabolical 

 cruelty, the Emperor Basil II. overthrew the 

 power of the Bulgarians, and, subduing the Serbs 

 likewise, re-established the immediate authority 

 of Constantinople as far as the Danube. 

 From this time forth the contest for supremacy 



