<P> The history of Christianity in Britain covers the religious organisations, policies, theology, and popular religiosity since ancient times . </P> <P> The early history of Christianity in Britain is highly obscure . Medieval legends concerning the conversion of the island under King Lucius or from a mission by St Philip or Joseph of Arimathea have been discredited; they seem to have been pious forgeries introduced in attempts to establish independence or seniority in the ecclesiastical hierarchy formalized following the Norman conquest of England and Wales . The first archaeological evidence and credible records showing a community large enough to maintain churches and bishops dates to the 3rd and 4th centuries, but it started from a small base: the British delegation to the 353 Council of Rimini had to beg for financial assistance from its fellows in order to return home . The Romano - British population seem to have been mostly Christian by the Sub-Roman period, although the Great Conspiracy in the 360s and increased raiding around the time of the Roman withdrawal from Britain saw many enslaved . The Saxon invasions of Britain destroyed most of the formal church as they progressed, replacing it with a form of Germanic polytheism . There seems to have been a lull traditionally attributed to the Battle of Badon but, following the arrival of Justinian's Plague around 547, the expansion resumed . By the time Cornwall was subjugated by Wessex at Hingston Down in 838, however, it was largely left to its native people and practices . </P> <P> Christianity was largely reintroduced to Britain by the Gregorian Mission, c. 600 . Establishing his archdiocese at Canterbury, St Augustine failed to establish his authority over the Welsh church at Chester but his mission--with help from Scottish missionaries such as SS Aidan and Cuthbert--proved successful in Kent and then Northumbria: the two provinces of the English church continue to be led from the cathedrals of Canterbury and York (est. 735). Owing to the importance of the Scottish missions, Northumbria initially followed the native church in its calculation of Easter and tonsure but then aligned itself with Canterbury and Rome at the 664 Synod of Whitby . Early English Christian documents surviving from this time include the 7th - century illuminated Lindisfarne Gospels and the historical accounts written by the Venerable Bede . The Irish and Scots adopted the Roman practices over the 7th & 8th centuries; around 768, "Archbishop" Elfodd of "Gwynedd" finally convinced the Welsh to follow, although it was not until after the reign of Bernard that the bishop of St Davids was finally compelled to submit to the authority of Canterbury and the English church . </P>

When did christianity come to the british isles