THE NORTHMEN AND OTHER INVADERS 229 for a time in order to blind his ruling son, who had turned back again toward heathenism. Boris replaced him by a j younger brother, Symeon, who had been educated at Con-
- stantinople and who lived like a hermit, touching neither
meat nor wine. Symeon, however, was ambitious and tried
- to conquer Roumania and to become emperor of Constan-
i tinople. The Byzantine Empire stirred up against him the ! Magyars, then located in Bessarabia; but he too found allies i in the Turks of the Pontus Steppe. The Magyars were de-
- feated and driven into Hungary, whence they began the
I series of westward invasions already recounted. Constan- tinople had to pay the Bulgarians tribute. In 904, Arab corsairs further weakened the Byzantine Empire by seizing Saloniki at the head of the JEgean Sea. In a second Bul- garian war (913-927) Thrace and Serbia, whose prince was a vassal of the Byzantine emperor, were almost depopu- lated, but Croatia held out against the Bulgarian advance. Before his death in 927, Symeon made an alliance with the Fatimites in North Africa. His pious son, Peter, however, I made peace with Constantinople ; and during his reign the I Magyars ravaged eastward as well as westward, and forced f both Bulgaria and the Byzantine Empire to pay them trib- ! ute. The Serbians, who had been driven from their country i in the recent Bulgarian war, took advantage of this setback I for Bulgaria to return to their homes. But of either Serbia or Croatia we know nothing more during the remainder of ithe tenth century. The Emperor Constantine VII (911-959), called Porphy- rogennetos from his birth in the purple room of the palace at Constantinople, has left us, among his nu- Other merous writings on agriculture, economics, laws, ^tem ° f ■ morals, tactics, and court etiquette, a treatise Europe On the Administration of the Empire, in which he refers to the various barbarian peoples on the northern and I eastern frontiers of the Byzantine Empire. What is now ■ Roumania and southwestern Russia — in other words, the region from the mouth of the Danube to the Sea of Azov — i was then held by the Petchenegs or Patzinaks, a fierce and
