Celtic religion encompasses the beliefs and rituals of the ancient Celts, an Indo-European people who peaked in their influence and territorial range in the 4th century BC. At this time, the Celts extended from the shores of Britain to Asia Minor. Following the 3rd century BC, their prominence began a protracted decline, culminating with Julius Caesar’s campaigns in Gaul between 58 and 51 BC, which effectively ended Celtic autonomy on the mainland of Europe. While Britain and Ireland experienced a slower degradation of traditional culture, factors such as political subjugation gradually eroded their customs. Presently, Celtic languages endure only in limited regions of Ireland, Scotland, Wales, and Brittany, largely due to historical migrations from Britain between the 4th and 7th centuries AD. Consequently, the tumultuous history of the Celts has significantly influenced the recording of their cultural and religious frameworks.
Sources of Information
Information pertaining to Celtic religion primarily stems from two sources: the sculptural artifacts associated with the continental Celts and those from Roman Britain, alongside the insular Celtic literary traditions that have survived from medieval eras. Both sources present challenges in interpretation. A majority of the monuments and their inscriptions originate from the Roman era, displaying a notable amount of syncretism between Celtic and Roman deity figures. Moreover, even interpretations of elements appearing to trace back to pre-Roman traditions remain complicated due to the absence of preserved mythological texts.
It wasn’t until centuries later—starting in Ireland during the 7th century and even later in Wales—that a formal mythological tradition began to be documented. However, by this time, both regions had undergone Christianization, resulting in these manuscripts being produced by monastic scholars. Although the resulting literature is rich and diverse, it exists in a context that is distanced both temporally and physically from its continental counterparts in terms of epigraphic and iconographic records, thereby reflecting the inherent selectivity as well as the influence of Christian scholarship from the redactors.
Despite these complexities, it is notable that there is considerable alignment between the insular texts and the evidence found on the continent. This similarity is particularly emphasized in the accounts of Classical writers such as Poseidonius, who documented their direct observations concerning the Celts.
