Founded in 1936 by Rafig Tullou, Morvan Marchal, and Francis Bayer du Kern, Kredenn Geltiek Hollvedel grew out of the Breton Federalist Movement as an attempt to reassert ancient Celtic religious beliefs.

The group's explicitly anti-Catholic and Modern Druidic ideology wanted to distinguish it from the existing non-religious Gorsedd of Brittany.

They mixed readings of the Bhagavad Gita and the maxims of Laozi with Celtic traditions to create an Indo-European esotericism as a basis for the re-creation of druidic worship.

Esotericist research by Gwilherm Berthou led to claims that ancient Celtic beliefs had been reconstructed.

During World War II, its journal, Kad (combat), devoted to druidic philosophy, changed its title to the less militaristic Nemeton ("Sanctuary").