Near the beginning of the period covered by this volume, Bishop Eusebius of Caesarea, the celebrated ‘father of church history’, composed two addresses in which he praised the accomplishments of Constantine’s reign. Toward its end, another Christian clergyman, the deacon Agapetus, addressed a series of aphorisms on kingship to the emperor Justinian. The two works serve as a convenient means to bracket the monumental changes that the church underwent during these centuries as it moved from the periphery to the centre of Roman social and political, as well as religious, thought. This is a story traditionally told in terms of Christianity’s ‘innate intolerance’ and imperial ‘Caesaropapism’, explaining at once the ruthless suppression of traditional religions that accompanied this movement and the intrusion of the state into the domain of the church. But these are concepts that (to borrow words coined for a vastly different situation) have by now outlived their uselessness. The writings of Eusebius and Agapetus open the way to a more complex, but also far more interesting, story, one that involves questions of imperial ideology, Christian identity, and demographic disruptions whose impact we have only recently come to appreciate.

The heavenly icon

The first of Eusebius’ two writings was a speech, ‘On the Holy Sepulchre’, composed for the eight-day Encaenia ceremony celebrating the dedication of Constantine’s magnificent Church of the Holy Sepulchre in Jerusalem in September 335. Ostensibly a reply to critics who thought the structure a waste of imperial resources and ‘frankly demeaning’, the speech is primarily a lengthy justification of the incarnation. In ch. 11, Eusebius sets out to demonstrate the many benefits that Christianity had produced.