In East as well as West, the bishops, saints, and missionaries were the true leaders of the nations into the unity of the Empire as well as the unity of the Church. [Sidenote: The Church's conquest of barbarism.] The idea of Christian unity saved the Empire and taught the nations. The idea of Christian unity was the force which conquered barbarism and made the barbarians children of the Catholic Church and fellow-citizens with the inheritors of the Roman traditions. If the dominant idea of the long period with which this book is to deal is the unity of the Church, seen through the struggles to preserve, to teach, or to attain it, the most important facts are those which belong to the conversion, to Christ and to the full faith of the Catholic Church, of races new to the Western world. The gradual extinction in Italy of the Goths, the conversion of the Franks, of the English, of many races on distant barbarian borderlands of civilisation, the acceptance of Catholicism by the Lombards and {5} the Western Goths, do not complete the historical tale, though they are a large part of it: there was the falling back in Africa and for a long time in Europe of the settlements of the Cross before the armies of the Crescent. There were also two other important features of this long-extended age, to which writers have given the name of dark. There was the survival of ancient learning, which lived on through the flood of barbarian immigration into the lands which had been its old home, yet was very largely eclipsed by the predominance of theological interests in literature. And there was the growth of a strong ecclesiastical power, based upon an orthodox faith (though not without hesitations and lapses), and gradually winning a formidable political dominion. That power was the Roman Papacy. [1] Bryce, _Holy Roman Empire_, p. 13, ed. 1904. {6} CHAPTER II THE EMPIRE AND THE EASTERN CHURCH (461-628) When the death of Leo the Great in 461 removed from the world of religious progress a saintly and dominant figure whose words were listened to in East and West as were those of no other man of his day, the interest of Church history is seen to turn decisively to the East. [Sidenote: Character of the Greek Church.]