The patristic authors of fourth-century Alexandria and the desert monks of Egypt are two distinct groups, but their chronological and geographic proximity, as well as personal relationships, make it convenient to bring them together into one chapter.

Before introducing them it is necessary first to make a few observations about the state of Christianity at the time. The great event which serves to define the period was Constantine's decision in 313 to tolerate the new religion. Its result was that Christianity would develop from a persecuted minority into the established religion by the end of the century. This is reflected in Christian literature by the remarkable proliferation of outstanding authors writing in both the traditional genres and in new ones such as the homily and the epistle. The period from 313 to roughly 450 is arguably the greatest in the history of Christian literature. But with the opportunities of the new situation there arose new problems. For one, mass conversions brought about the phenomenon of religious laxity and nominal Christianity, and for another, much of the polemical energy formerly devoted to combating paganism had now to be directed against the internal enemy of heresy. The majority of these heresies arose in the course of the great theological struggle to define the nature of Christ, more specifically, to spell out the relationship between the human and divine aspects of his person, and in turn the relationship of his person to the others of the Trinity.