Ancient Irish history and legends have come down to us through history thanks to the diligent chronicling of the early Christian monks. The best record of the rich Celtic mythological tradition is contained in the four cycles drawn up by twelfth century Christian scribes: the Mythological Cycle, the Ulster Cycle (also known as the Red Branch Cycle) and the Fenian or Fianna Cycle, and the Kings, or Historical Cycle.
Irish myths were probably recorded in the eighth century or earlier, possibly written by the Druids in Ogham. There are few surviving examples of Ogham because this writing was primarily done on bark, or or wands of hazel and aspen. However the legends of the early Celtic people were also passed down through the tradition of storytelling, and it was from this source that the Monks gathered their colorful tales.
The early medieval monks rewrote the oral stories in a style that was designed to be read aloud to noble or royal households. When they set themselves the task of constructing a pseudo-history of Ireland, they also recast the ancient myths and legends into a Christian mold. In doing so, they demoted the old gods to mortals, and rewrote the sagas nto an almost indecipherable maze of conflicting events.
Fortunately, there are a number of manuscripts which have survived fairly intact, and there are many others not yet translated into English. The Lebor Gabála or "Book of Invasions" is one of a number of manuscripts from which our knowledge of Celtic pre-history is derived.
Joanna Hautin-Mayer has written:
"We know tragically little about the actual religious expressions of the ancient Celts. We have a few myths and legends, but very little archeological evidence to support our theories. We have no written records of their actual forms of worship, and the accounts of their culture and beliefs written by their contemporaries are often highly biased and of questionable historical worth."
Silver RavenWolf wrote in 1998:
"Wicca, as you practice the religion today, is a new religion, barely fifty years old. The techniques you use at present are not entirely what your elders practiced even thirty years ago. Of course, threads of 'what was' weave through the tapestry of 'what is now.' ...in no way can we replicate to perfection the precise circumstances of environment, society, culture, religion and magic a hundred years ago, or a thousand. Why would we want to? The idea is to go forward with the knowledge of the past, tempered by the tools of our own age."