Caesar’s list of the major deities of the Gauls mentions Mercury, Mars, Jupiter and Minerva, but also Apollo, ‘who drives away disease’. However, unlike Tacitus, who, a century and a half later, equates the Alci with Castor and Pollux (and this is the only explicit attestation of interpretatio romana), Caesar mentions only Roman theonyms, without letting us know what they represent. It would be methodologically incorrect to look for a single ‘hidden god’ behind Caesar’s Apollo, because the Gallic religion was multiple. Conversely, hypothesising a multitude of local gods, all different from each other, converging in Roman times under the name of Apollo would explain nothing. The truth probably lies somewhere in between: we can identify some recurring deities, as well as multiple phenomena of attraction. In the Celtic world, two deities with non-Latin theonyms correspond preferentially to Apollo, with complementary areas of distribution: Belenos in the south and Grannos in the north. There are about twenty epicleses of Apollo in the north-western provinces, but most are simply qualitative epithets (Apollo Anextlomaros, Atepomaros, Mogetimaros, Vatumaros, etc.) or topic. The self standing theonyms equated with Apollo (apart from Belenos and Grannos) are Maponos, Borvo, Vindonnus and Moritasgus. These are deities associated with springs, as are their consorts, Sirona and Damona. That’s not to say that Apollo in Gaul should be mechanically and universally linked to spring waters. The reality is more nuanced, as shown by the case of Apollo Moritasgus in his sanctuary at Alesia. Although the cult site is characterised by the presence of springs and numerous water-related features, the theonym Moritasgos is nevertheless linked to the sea and is in fact located on the great road that crosses Gaul towards the Ocean.
