"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."

WOW! Caesar had not come across the Druids in Gaul! That's not what you read in his 'De Bello Gallico' books I,II,III & IV.

It seems to me that the article implies that Druidism was very new to archipelagian (insular I mean, nothing to do with Pelagius) Celtic society. Had not it been a part of Celtic society for a number of centuries? Hallstat & La Tene ?? The Celts, being illiterate, depended on the druids to transmit knowledge, in the form of triads & other poetic forms. A bloodthirsty priesthood? A recent tv programme here showed Caesar to be so bloodthirsty in his conquest of Gaul that it threatened his political hegemony in Rome. He would have spun a lot in his ‘De Bello Gallico’, all 4 books!

"In Roman Britain, Christianity took root in the poorer ranks of society living outside the highly Romanized towns. Such areas in the south were still within the sphere of Roman influence, but in spite of three centuries of Imperial rule, the majority of Christians in Britain were of Celtic background. When Rome abandoned Britain, both spiritually and politically, the majority of British Christians fled to the west amid the onslaught of Angle, Saxon, and Jute invasions. Isolated from Roman Christianity until St. Augustine's mission in 597 AD, the period was a turning point in the further development of Christianity in England."

But most of the Teutons in Britain were converted by the Celtic Church. The ethnic cleansing theory is very debatable. Gregory needed to send Augustine to Britain to enforce orthodoxy, acheived at Whitby in 664.