As is well known, Orderic began his Historia ecclesiastica as a history of his own monastery, Saint-Évroul in Normandy, but progressively expanded it to what is almost a comprehensive history of contemporary Christianity, embracing a geographical area from Spain to the Holy Land, from England to Sicily, with, however, a strong focus on the Anglo-Norman world. At a certain stage of the composition, Orderic decided to place two additional books ahead of this Norman history (the original Book I became Book III, and so on) dedicated to apparently quite different themes. Most of Book I consists of a kind of Gospel harmony, an extensive life of Christ, followed by the history of the apostles up to the descent of the Holy Spirit; a brief world chronicle ordered by the reigns of the Roman emperors fills the chronological gap between Pentecost and Orderic's present time. Book II contains the (also very extensive) lives of the apostles and evangelists and a second chronicle, arranged chronologically by the pontificates of the Roman popes.

Modern scholarship has made little attempt to understand and explain the relationship between these two books and the rest of the work, and the fact that in Marjorie Chibnall's edition they appear only in the form of summaries and extracts has not helped to clarify their role in Orderic's general project. This chapter will stress the coherence of Orderic's work as a whole, and, by summing up and developing in greater detail some points of a previous study, I will show that by introducing Christ and some of the major figures of early Christendom as distinctive subjects, Orderic clarifies a meaning present in his narration from the beginning. I will suggest further that this meaning is not simply a question of moral judgement, but implies a fully coherent theology of history, which has been mostly neglected or misunderstood by modern observers because it was uncommon at Orderic's time, and does not correspond to our current conceptions concerning this matter.

In Chibnall's view the Historia ecclesiastica is made of two heterogeneous components which, however, ‘were loosely but persuasively joined by the metaphor of the vine’.