Fifty-five years before the birth of Jesus Christ, Julius Caesar encountered the Druidic religious culture in his invasion of Britain. Although only recently established in Caesar's day, the Druids exerted tremendous influence over British society; they were the priests of the primitive government, and possessed considerable authority as such. In addition to their spiritual duties, Druid priests were responsible for educating the youth, remained immune from military duty and taxes, and presided over civil and criminal legal matters (to the point of deciding controversies among states). They were the expression of both a local government and a community spirituality that were bound to a larger whole. They ruled with an iron fist - decisions by Druid priests were final and irrefutable. Their penalties were swift and severe, with many individual Celts and Britons banished from contact with civilization. Many aspects of Druidic culture surfaced in the formation of Celtic Christianity.
Druidism was a polytheistic cult with a naturist bent: gods and goddesses were believed to inhabit local springs, caves, forests, and mountains, and became the personification of natural objects and events. The entire social structure, both as local community and as loose nation-state, was a caste system, with the Druid priests presiding above all. Caesar viewed them with contempt; he found their brutality and centrality immediately threatening, and wrote of the Druids:
All the Gauls are as a nation much given to superstition, and, therefore, persons afflicted by severe illness or involved in wars and danger either make human sacrifices or vow to do so, and use the Druids as their ministers in these ceremonies. The Germans differ much from the Gauls in these customs. For they have no Druids to preside over their religion.
Druidic paganism was destined to be replaced with the advent of further Roman expeditions into the islands, and finally the full annexation of Britain by Rome. Caesar did little more than establish a foothold on the island; Britain officially became a frontier province of the Empire with the invasion of the emperor Claudius' troops in 43 AD.
The Roman Empire was approaching the height of her power as Britain became her furthest frontier. The Roman army evolved into an institution of social mobility as Britain was romanized in the first and second centuries. Roman legions embarked on a campaign of terror against the Druids, as the latter refused polytheistic Roman religious beliefs, and thus rejected Roman governmental prerogative. Roman religion, much like Druidism, was inherently intertwined with politics. For Britain to be subjugated under the authority of Rome, the rebellious Druids had to be exterminated. The army paved the way for a flourishing Roman culture in southern England by the early second century.
Social conditions in Rome and dissatisfaction with the corrupt Roman government left many peasants in search of a spiritual fulfillment that was lacking in Roman religious institutions. Jews received a high level of tolerance from the state in their religious practices, as long as they maintained loyalty to the empire. The advent of Christianity in the mid-first century, however,...