This is a story book. It is now fourteen years since I planned the story related in these volumes, the outcome of a series of lectures which I had occasion to deliver on the period of the Roman dominion in Egypt. But the pleasures of inventive composition were forced to give way to scientific labors, and when I was once more at leisure to try my wings with increase of power I felt more strongly urged to other flights. Thus it came to pass that I did I not take the time of Hadrian for the background of a tale till after I had dealt with the still later period of the early monastic move in Homo Sum. Since finishing that romance my old wish to depict, in the form of a story, the most important epoch of the history of that venerable nation to which I have devoted nearly a quarter century of my life, has found its fulfilment.