The Druids were also the chief providers magic and supernatural wisdom in Celtic society. Ritual cursing "riddles and dark sayings" (Diogenes Laertius) are ascribed to them. It is also likely that they had some knowledge of herbs and herb lore.
It seems likely that the British Isles was the centre of Druid beliefs and Caesar tells us that Gaulish Druids were sent to Britain to be trained. It is probable that British Druids met together regularly each year on a fixed date in the same manner as their Gaulish counterparts, who assembled at a sacred place in the land of Carnutes (ancient Chartres).
The Irish literary sources provide us with many references to Druids. In the Book of Invasions Partholon, one of the invaders, arrives with three Druids, Finn (hero of the Fionn Cycle) is reared by a Druidess and the goddess Bidgit is born in a Druids household. The most famous literary Druid is however Cathbadh, a member of the Ulster King Conchobars' household and a figure of great importance. Cathbadh is well recorded for his great powers of divination and seeing into the future.
The Druidic religion came to an end as a result of successive rounds of persecution by the Roman authorities. In AD 64 the Romans sacked the island of Anglesey in an effort to bring Druidism to a final end. There are a number of possible reasons why the Romans pursued this course of action including the wish to stop the human sacrifices (which they found disgusting to their sensibilities) and the wish to put an end to what might have been a nationalistic and political focus inherent in Druidism.