One of the most striking facts connected with the Celtic religion is the large number of names of deities which it includes.  These names are known to us almost entirely from inscriptions, for the most part votive tablets, in acknowledgment of some benefit, usually that of health, conferred by the god on man.  In Britain these votive tablets are chiefly found in the neighbourhood of the Roman walls and camps, but we cannot be always certain that the deities mentioned are indigenous.  In Gaul, however, we are on surer ground in associating certain deities with certain districts, inasmuch as the evidence of place-names is often a guide.  These inscriptions are very unevenly distributed over Gaulish territory, the Western and the North-Western districts being very sparsely represented.

In the present brief sketch it is impossible to enter into a full discussion of the relations of the names found on inscriptions to particular localities, and the light thus thrown on Celtic religion; but it may be here stated that investigation tends to confirm the local character of most of the deities which the inscriptions name.  Out of these deities, some, it is true, in the process of evolution, gained a wider field of worshippers, while others, like Lugus, may even have been at one time more widely worshipped than they came to be in later times.  Occasionally a name like Lugus (Irish Lug), Segomo (Irish, in the genitive, Segamonas), Camulos, whence Camulodunum (Colchester), Belenos (Welsh Belyn), Maponos (Welsh Mabon), Litavis (Welsh Llydaw), by its existence in Britain as well as in Gaul, suggests that it was either one of the ancient deities of the Aryan Celts, or one whose worship came to extend over a larger area than its fellows.  Apart from a few exceptional considerations of this kind, however, the local character of the deities is most marked.

A very considerable number are the deities of springs and rivers.  In Noricum, for example, we have Adsalluta, a goddess associated with Savus (the river Save).  In Britain ‘the goddess’ Deva (the Dee), and Belisama (either the Ribble or the Mersey), a name meaning ’the most warlike goddess,’ are of this type.  We have again Axona the goddess of the river Aisne, Sequana, the goddess of the Seine, Ritona of the river Rieu, numerous nymphs and many other deities of fountains.  Doubtless many other names of local deities are of this kind.  Aerial phenomena appear to have left very few clear traces on the names of Celtic deities.  Vintios, a god identified with Mars, was probably a god of the wind, Taranucus, a god of thunder, Leucetios, a god of lightning, Sulis (of Bath) a sun-goddess, but beyond these there are few, if any, reflections of the phenomena of the heavens.  Of the gods named on inscriptions nearly all are identified with Mercury, Mars, or Apollo.  The gods who came to be regarded as culture-deities appear from their names to be of various origins: