Iulius Valerius Alexander Polemius is the name of the author of the Latin translation of the Greek Alexander Romance, as transmitted by the suscriptiones of the Turin palimpsest, the oldest witness of the Latin text (Res Gestae Alexandri Macedonis). The palimpsest dates to the 8th century AD, and was lost in the fire of the Turin National Library in 1904. The suscriptiones also call him vir clarissimus. Some scholars suggest he is the same person as the Polemius who was consul in 338 AD, but the sources give Flavius as the name of the consul’s gens; the identification is doubtful, even if late-antique onomastic usages were not rigid. Other scholars suggest he may be the same person as the Polemius mentioned by Athanasius among the comites of Constantius II who were ordered to write to Athanasius, recalling him to Alexandria. This identification would imply that Valerius was a Christian, which is inconsistent with the pagan content of the Res gestae.

Some elements of this work suggest that he was very probably of African origin, possibly from Alexandria: the descriptions of Egyptian places appears to derive from first-hand knowledge; the size of Alexandria is emphasised more than in the extant Greek versions of the Alexander romance; the citizens of Pharos and Alexandria are called nostri (D. Romano). On the other hand, some scholars have claimed that a number of difficult passages in the Res gestae can be explained by assuming Iulius Valerius misunderstood the Greek text. This would conflict with the hypothesis that the author was a native speaker of Greek, unless the mistakes were already present in the Greek original translated by Iulius Valerius. The hypothesis that Iulius Valerius was also the author of the Itinerarium Alexandri is controversial and, in fact, impossible to ascertain. [R. Tabacco; tr. di L. Battezzato]