Gaulish religion is known mainly through Roman eyes and Roman habits of translation. Caesar reported that the Gauls worshipped Mercury above all, then Apollo, Mars, Jupiter and Minerva, and that practice of naming a foreign god by the nearest Roman equivalent is why so many dedications from Gaul carry a double name: Mercurius Dumias, Mars Lenus, Apollo Grannus. Miranda Green's work on the wheel symbol traces one of the emblems that does not translate, carried by a sky god the Romans assimilated to Jupiter.
The inscriptions themselves, catalogued in John Koch's encyclopedia, name hundreds of deities, most of them attached to one spring, one grove or one people. Epona, the horse goddess, is the exception that travelled, taken up by Roman cavalry and honoured as far as Rome itself. The mother goddesses, the Matres, appear in threes across Gaul, Britain and the Rhineland.
The archaeology shows sanctuaries with enclosures and deposits of weapons and animal bone, as at Gournay-sur-Aronde, and votive offerings placed in rivers, springs and bogs. The wooden figures left at the source of the Seine were models of the parts of the body a petitioner wanted healed, which is one of the few places in the record where the intention behind an offering can be read directly rather than inferred.