Cernunnos is a Celtic god whose name is only clearly attested once, on the 1st-century CE Pillar of the Boatmen from Paris, where it is associated with an image of an aged, antlered figure with torcs around his horns.
Through the Pillar of the Boatmen, the name "Cernunnos" has been used to identify the members of an iconographic cluster, consisting of depictions of an antlered god (often aged and with crossed legs) associated with torcs, ram-horned (or ram-headed) serpents, symbols of fertility, and wild beasts (especially deer). The use of the name this way is common, though not uncontroversial. As many as 25 depictions of the Cernunnos-type have been identified. Though this iconographic group is best attested in north-eastern Gaul, depictions of the god have been identified as far off as Italy (Val Camonica) and Denmark (Gundestrup).
Cernunnos has been variously interpreted as a god of fertility, of the underworld, and of bi-directionality. His cult (attested as early as the 4th century BCE) seems to have been largely unaffected by the Roman conquest of Gaul, during which he remained unassimilated to the Roman pantheon. Cernunnos has been tentatively linked with Conall Cernach, a hero of medieval Irish mythology, and some later depictions of cross-legged and horned figures in medieval art.