Celtic religion encompasses the spiritual beliefs and practices of the ancient Celtic people. This group, categorized under an ancient Indo-European lineage, reached the pinnacle of their power during the 4th century BC, extending their influence across Europe, from Britain to the outskirts of Asia Minor. However, beginning in the 3rd century BC, the Celtic civilization began a gradual descent towards fragmentation. The conquest of Gaul by Julius Caesar between 58–51 BC marked a definitive end to Celtic autonomy on the European mainland. Although the decline was more gradual in Britain and Ireland, the traditional Celtic culture was steadily eroded due to political domination. Today, Celtic languages are predominantly found in specific areas of the west of Europe, notably regions of Ireland, Scotland, Wales, and Brittany—a preservation largely facilitated by migration from Britain in the 4th to 7th centuries AD. Thus, the tumultuous and fragmented history of the Celts has made it challenging to thoroughly document their cultural and religious frameworks.
Sources of Information
Information regarding Celtic religion is primarily derived from two significant types of sources: sculptures associated with the Celts of continental Europe and Roman Britain, along with surviving insular Celtic texts from medieval times. Each of these sources comes with its own set of interpretative challenges. Most of the sculptural monuments and their inscriptions date back to the Roman era, exhibiting a blend of Celtic and Roman deity influences. Even though certain figures and symbols may stem from pre-Roman traditions, their meanings remain elusive without a preserved mythological literature. It wasn’t until several centuries later—starting in the 7th century in Ireland and even later in Wales—that the mythological narratives began to be documented in writing. However, by this time, both Ireland and Wales had undergone Christianization, and the scribes who recorded these tales were primarily monastic scholars. Consequently, the resulting literature is rich and diverse yet detached from the initial context of its epigraphic and iconographic examples on the Continent. It naturally reflects the biases and Christian influences of the compilers. Despite these challenges, it’s noteworthy that there are many similarities between the insular literature and the evidence found on the Continent. This concordance is especially evident in the observations made by Classical commentators, starting from Poseidonius (c. 135–c. 51 BC), who chronicled their own or others’ observations concerning the Celts.
