On the penultimate page of the main text of his new study of Constantine, Charles Odahl notes that he ‘found [himself] in agreement with [T.D. Barnes’s] opinion that Constantine “believed sincerely that God had given him a special mission to convert the Roman Empire to Christianity” ’ (p. 283, quoting T.D. Barnes, Constantine and Eusebius [Cambridge, MA, 1981], p. 275). This prompts an obvious question: do we need a book that substantially agrees with another, already well-established as a major study in the μeld, and published over twenty years ago? O. is clearly of the opinion that we do. His aim is to exploit a broader range of sources than simply texts, of which Barnes was (and remains) a subtle exegete. He laments the ‘failure [of earlier studies] to completely utilize all the material sources from the period – particularly the coins and buildings – in conjunction with the literary sources in order to o¶er a full and accurate portrait of Constantine and his secular and religious policies’ (p. 283). Thus, in his conclusion (and similar remarks are made in the Preface: pp. viii–ix), O. seeks to justify his lengthy biographical account of the emperor. How successfully does the result match this ambition?