In the centuries before Christianity reached Ireland the druids exercised great influence, not merely as priests but also as learned men who could judge disputes and advise kings. Their training lasted possibly a dozen years, and their traditions were passed on orally. The druids practised magic and claimed to foretell the future. They conducted public sacrifices, offering captured animals to the gods after a successful battle, and possibly there were on occaslon human sacrifices. In time two other important groups emerged, the lawyers, or brehons, and the poets or filidh. Christianity meant the end of the druids, but the poets and lawyers continued to have an important place in Irish society.

The brehons were professional lawyers, and when disputes arose, it was to them that people turned as arbitrators, for there was no public enforcement of law. There was a complicated system of sureties to make certain that contracts were fulfilled or that the parties to an arbitra tion accepted its outcome.

The filidh were more than poets. In addition to com posing and reciting poetry they were custodians of the hlstory, mythology and genealogy of the Celts. In the Christian era they acquired much of the authority which had once belonged to the druids, and did much to preserve Irish tradition and learning at a time when the monasteries looked to the Continent for inspiration.

The earliest surviving Irish manuscripts are written in Latin, and are copies of the Gospels and the Psalms. The sagas of Celtic Ireland are found in much more recent vellum manuscripts, compiled in the twelfth century and later, although the language suggests they were copied from earlier works dating as far back as the ninth century. The most important manuscripts are the Book of Leinster and the Book of the Dun Cow, both from the twelfth century, and the Yellow Book of Lecan from the fourteenth century. These manuscripts contain the often heroic tales which the filidh handed down from generation to generation, and which are a blend of history, pagan belief and deliberate fiction.