What was the year of Christ's nativity? The answer of Dionysius Exiguus still determines our chronologies, though the origin of the reckoning may be camouflaged by the substitution of ‘common era’ for ‘anno domini’. The first computation, however, was that of Julius Africanus, whose chronicle of 221 reached a watershed at the year 5500 from the creation. So much we know, and we know in addition that Africanus dated the events of the last millennium by Olympiads, taking up his pen in the 250th of these four-year cycles. But what his sources were, whether the regnal years to which he also appeals began with the accession of the king or with the first New Year of his tenure, and where his date for the birth of Christ would fall on the Dionysian axis – these are questions that have molested scholars for half a millennium, and to which even now no one reply is given by the eminent contributors to this volume. The difficulties which attend the interpretation of figures in any ancient text are compounded, as Wallraff notes in a piece introducing his own forthcoming edition of the Chronicle, by the fragility of the evidence used in previous attempts to detect unacknowledged plagiarisms from Africanus. On the other hand, conjecture may be overtaken by a new discovery, like the fragment discussed by Gregor Staab, which treats the Timaeus of Plato as a glossary on the Septuagintal account of the creation. Richard Burgess, relying chiefly on calculations attested in more than one later source, concludes that ‘Africanus dated the Incarnation … to autumn 4 B.C. – autumn 3 B.C.’ (p. 42); on the other hand, Alden Mosshammer, having sieved all the phenomena with practised ingenuity, pronounces that ‘Africanus dated both the Incarnation and the Nativity to the year 5501, equivalent to 1 B.C.’ (p. 112). Even the aim of the project is in doubt, for it can hardly be fair to say, with Umberto Roberto, that Africanus was ‘kein Apologet’ (p. 15), if Osvaldo Andrie is right to credit him with the creation of an absolute chronology of world events, which vindicates the ‘universality of Christian time’ (p. 145). Andrie holds, none the less, that the Synagoge which he attributes to the western writer falsely called Hippolytus improved on Africanus by composing a work that ‘referred on all levels to Christ’. Very different, in William Adler's view, was the object of Eusebius, whose criticisms of Africanus expose the pretensions of the Greek chronographers whom he consulted. In the second half of the volume, Latin chroniclers are discussed by Anna-Dorothee von den Brincknen and Hans-Werner Goetz, other Greeks by Katherina Heyden and Staffan Wahlgren, Armenians by Armenuhi Drost-Abgarian, Nestorians by Karl Pingérra, Ethiopic chronology by Witold Witakowski and a late Ethiopian scion of Africanus by Manfed Kopp. My only animadversion, as an outsider, is that all these studies assume that the chronographers made fewer mistakes than were commonly perpetrated in an age which lacked a zero, a positional number system and the electric calculator.