Most of what is known about elements of this original belief system is based on the analysis of legends, the study of place names and scant historical references to pagan rituals practised by the Basques.
Većina onoga što znamo o elementima tog sustava vjerovanja temelji se na analizi legendi, proučavanju imena mjesta i oskudnim povijesnim referencama na poganske rituale koje su prakticirali Baski.