EXPANSION OF CHRISTENDOM 309 overlordship of Constantinople, by whose territories they were surrounded on the east, south, and southwest. For
- both the politics and the culture of Constantinople at this
epoch our chief sources of information are the hundreds of treatises on varied subjects, the history, and the letters, of Psellus, a prolific writer of the eleventh century who was . interested in everything under the sun as well as in theology. In 1057, after reigning at Constantinople for nearly two centuries, the Macedonian dynasty died out, and for a generation there was confusion and anarchy in Rise of th the Byzantine Empire. Meanwhile the peren- Seljuk Turks nial migration of Asiatic nomads westward had been renewed by the Turks. A branch of this race, known as the "Petchenegs" or "Patzinaks," had been for some time on the lower Danube. It was to protect their eastern frontier against this tribe that the Hungarians introduced German settlers into Transylvania in the later twelfth century. Another branch, known as the "Seljuk Turks," from their legendary hero-founder, became in the eleventh century the ruling element in the Moslem world. After con- quering Persia they accepted Islam and entered the service of the Abbassid caliphs at Bagdad. The result was that the caliph soon ceased to be anything more than the nominal religious head of the Mohammedan world, while a Turkish sultan held all the military and political power. The Seljuks spread into Syria, Armenia, and Asia Minor; in 107 1, at Manzikert in Armenia, they won a decisive victory over the Byzantines, and soon had taken away all of Constanti- nople's Asiatic territories. «The Turks were ignorant and fanatical barbarians like e Almoravides and Almohades, and had a like evil effect upon Arabian culture. The heyday of Bagdad, Effect of like that of Cordova, as a center of civilization Turkish was now over, and the days of Constantinople Arabian were numbered. It was time for the teeming culture and expanding population of feudal western Europe to take up the torch of civilization. The Turks not only showed no bent for the remains of Greek, Persian, Syrian, and Arabian