A druid was a member of the ruling class in ancient Celtic cultures. Druids were primarily religious leaders as well as legal authorities, adjudicators, lorekeepers, medical professionals and political advisors. In Ireland and Great Britain, they held considerable influence over the masses until the rapid spread of Christianity would drive them to near-extinction.
By the late 9th century, the old druidic beliefs were completely gone save for a few followers, such as the priestess Deirdre Na Linni, Ollamh Érenn Ciara ingen Medba  and Halewyn.  A small group of druids known as the Children of Danu sought revenge against the kings of Ireland for abandoning the traditional Celtic faith in favor of Christianity and Norse paganism. They were dedicated to restoring the druidic religion throughout Ireland and eliminating any rival faiths. However, they were annihilated by jarlskona Eivor Varinsdottir of the Raven Clan.