druids (drōˈĭdz) [key], priests of ancient Celtic Britain, Ireland, and Gaul and probably of all ancient Celtic peoples, known to have existed at least since the 3d cent. BC. Information about them is derived almost exclusively from the testimony of Roman authors, notably Julius Caesar, and from Old Irish sagas, supplemented to some extent by archaeological evidence. The druids constituted a priestly upper class in command of a highly ritualistic religion, which apparently centered on the worship of a pantheon of nature deities. Druids were also responsible for the education of the young and generally for the intellectual life of the community; although apparently literate, they taught by oral transmission, and their courses are said to have lasted as long as 20 years. The druids believed in immortality of the soul in a nonjudgmental world of the dead. Their religious ceremonies seem to have been performed chiefly in tree groves (the oak and the mistletoe that grows on the oak were held sacred) and at river sources and lakes. The druids performed animal and human sacrifices and practiced divination and other forms of magic. Tacitus mentions a Celtic tribe, the Bructeri, that was led by a prophetess, and Irish legend confirms that there were women druids, although their precise role is not known. According to Caesar, the druids in Gaul were organized into a federation or brotherhood that extended across tribal divisions and was headed by an archdruid; they met once a year, probably on the site of Chartres, to arbitrate private and intertribal disputes. They thus wielded great political power and were an important cohesive force among the Celtic tribes. The druids in Gaul were the core of the rebellions against Rome. Their power, although broken by the Romans, finally yielded only to Christianity. In the late 18th and 19th cent., interest in the druids was spurred by archaeological discoveries and by the romantic movement. The megalithic monuments of France and Great Britain, notably those at Carnac and Stonehenge, were once ascribed to them, but these are now known to predate Celtic culture.
See S. Piggott, The Druids (1968, repr. 1985); A. Ross, Druids, Gods, and Heroes (1986); W. Rutherford, The Druids: Magicians of the West (1986).