This is an English translation of a work originally written in Italian and first published in 1995. It is a vast undertaking incorporating as it does material from the New Testament period to the sixth century ce. The two volumes are divided into nineteen and twenty-two chapters respectively. Some of these divisions have been determined by genre (the letters of Paul and the Pauline tradition, the Gospel tradition, here including both canonical and apocryphal works, treaties in letter form, Christian poetry of the west), or concern individual writers of significance (Irenaeus, Clement of Alexandria, Augustine) or are linked to geography (the Christian literature of Africa) or specific themes (Christianity and education) or periods (the age of the tetrarchs and of Constantine). The volumes do not cover all the literature written by Christians in the relevant period, and this is especially the case in relation to the second volume which deals with a time with a literary deposit much richer than that of the period covered in the first volume (so, for instance, letters, conciliar documents, acts and canonical texts are not discussed in the second volume for here literature is deemed as something that does not have a purely practical purpose). Each chapter includes remarks of an introductory kind and then quite general discussions of the relevant literature. The bibliographies are, of course, not comprehensive. This is understandable, but on a number of occasions it seems that the choice of secondary literature is not always as good as it might have been, and it is perhaps to be regretted that the bibliographies have not been updated since 1995.