The practice of human sacrifice, apparently carried out by the Druids, is now known to have been a survival of pre-Druidic customs and more than probably was regarded as an efficient way of disposing of unpleasant elements in their society. Druids would have presided dispassionately at such ceremonies – in the sense of being guardians of the correct balance within the community rather than being wanton murdering high priests. Indeed, the Druids seem also to have presided over traditional religious ceremonies, such as the placing of deliberately broken objects in the water of streams and wells as offerings to the gods.
Accounts are given also of the ritual harvesting of mistletoe. This had to be cut with a golden knife or sickle and gathered without it being contaminated by touching the ground, the plant is caught in a white cloth by attendants waiting below. Two white bulls were then sacrificed, after which the priest divided the branches into many parts and distributed them to the people, who hung them over doorways as protection against thunder, lightning, and other evils.
The folklore, along with the magical powers of this plant, blossomed over the centuries. It was understood, for instance, that mistletoe took on the character of its host tree in some ways.
Mistletoe grown on oak was in very subtle ways different from mistletoe grown on apple trees. A sprig placed in a baby’s cradle would protect the child from fairies. An entire herd would be protected from harm if a sprig were given to the first cow calving after New Year.
In both Gaul and Ireland, Druids were not just representatives of a religion but an integral part of the community. Written records seem to prove that Druids had withdrawn from Gaul in the face of the Roman army by the end of the 1st century CE, but there continues to be evidence of their existence in Ireland much later. The similarities between the Irish and Gallic Druids are quite pronounced. In Ireland, They were most often found in the service of kings, in the role of advisers as a result of their skills in the use of magic and the voice as a vehicle.