Christian history begins with the triumph of the Church. With Eusebius of Caesarea the apologetic pamphlets of the age of persecutions gave way to a calm review of three centuries of Christian progress. Eusebius' biography of Constantine shows what distortion of fact the father of Church history permitted himself, but the Ecclesiastical History was fortunately written for those who wanted to know what really happened, and remains to-day an invaluable repository of Christian antiquities. With the continuations of Socrates, Sozomen and Theodoret, and the Latin manual which Cassiodorus had woven from them (the _Historia tripartita_), it formed the body of Church history during all the middle ages. An even greater influence, however, was exercised by Eusebius' _Chronica_. Through Jerome's translation and additions, this scheme of this world's chronology became the basis for all medieval world chronicles. It settled until our own day the succession of years from the Creation to the birth of Christ,--fitting the Old Testament story into that of ancient history. Henceforth the Jewish past,--that one path back to the beginning of the world,--was marked out by the absolute laws of mathematics and revelation. Jerome had marked it out; Sulpicius Severus, the biographer of St Martin, in his _Historia sacra_, adorned it with the attractions of romance. Sulpicius was admirably fitted to interpret the miraculous Bible story to the middle ages. But there were few who could write like him, and Jerome's _Chronicle_ itself, or rather portions of it, became, in the age which followed, a sort of universal preface for the monastic chronicler. For a time there were even attempts to continue "imperial chronicles," but they were insignificant compared with the influence of Eusebius and Jerome.