INTRODUCTION TO SOCIOLOGY 415
Lombards, nor the Huns and other barbarians, from invading the empire either with violence or by means of concessions of lands.
On the other hand, the Christian church continued to spread and to become organized. It became centralized through the establishment of its hierarchy. From the middle of the fifth century it was divided into five provinces or patriarchates : Rome, Constantinople, Antioch, Jerusalem, Alexandria, besides the autonomous province of Cyprus. The boundaries of these divi- sions were modeled, at least in the East, upon the civil boundaries. The city had its bishops; the chief place of the province, its metropolitan ; the patriarch was at the head of one or of several dioceses. Just as the temporal power was divided between the East and the West, so the bishop of Constantinople tended to become the pope of the Eastern church. The council of 381 had given him the first place after the bishop of Rome. In the sixth century he became ecumenical patriarch, in spite of the popes of Rome, who were sole patriarchs of the West.
Just as kingdoms were founded at the expense of the empire both at home and abroad, so too there were formed national churches in Ethiopia, in Persia, in Armenia, and in Iberia. These churches were, at the most, vassals of the patriarchs of Alexan- dria, of Antioch, and of Constantinople. The feudal hierarchy was thus organized within the bosom of the government of souls. The bonds of this hierarchy, like those of the temporal hierarchy, were weak or powerful according to circumstances. From the end of the fifth century the church of Persia inclined toward Nestorianism ; that of Armenia, toward the Monophysite heresy.
In Gaul there existed a national church, with its vicariate at Aries. There was also the Celtic church of Bretagne and of Ire- land. In reality, it was, as always, through adaptations and differentiations, which went sometimes to the point of schism and heresy, that Christianity developed. In the second half of the sixth century its domain extended as far as Nubia, as well as among the pagans of the Caucasus and the Black Sea. In the West the barbarians, Burgundians, Suevi, Visigoths, at first Arians, went over to Rome ; the Lombards remained recalcitrant
