It is strange that the conversion of Britain, one of the major provinces of the Roman Empire, appears in the present state of evidence to have been a failure. How was it that St. Augustine found so few traces of Christianity in Britain, even in the kingdom ruled by Ethelbert in Kent which was closely allied to the Catholic kingdom of the Franks? For with the notable exception of the shrine of St. Alban on the hill above Verulamium, no trace of an organised Church remained in the areas of Britain ruled by the Angles and Saxons. There were no bishoprics, not even London or York, no churches, except ruins, no parishes or monasteries, such as were flourishing on the near-Continent. There was no representative of a British Church to greet St. Augustine when he landed with his monks on Thanet in 597. In the century and a half since the last ‘groan of the Britons’, i.e. their last recorded appeal for aid to the Patrician Aetius in Gaul in 446/7 the Church in eastern and central Britain had declined to a point near extinction. Why?

The literary evidence for Christianity in Britain in the first three centuries is not large but comparable with that of other outlying provinces of the empire in the west. Bede (c.731) retains the tradition of the martyrdom of Aaron and Julius at Caerleon. The vicus attached to a legionary fortress might be expected to contain Christians, for the military and merchants from the eastern provinces would be among the likely carriers of the new eastern religion to the west. Bede also gives a long extract from the Acta of the martyrdom of Alban. But whether either of these martyrdoms took place in the early third century, during the Decian persecution in 250, or the Great Persecution of 303–304 is uncertain.

Ten years after the end of the Great Persecution in the west, Britain was represented by three bishops at the Council of Arles on 1 August 314. This was the first major Council including all the western province and convoked by the emperor Constantine. It was designed initially to settle the dispute between Caecilian, bishop of Carthage and his Donatist opponents. However, the Council quickly turned to other business, such as the date of Easter, the non-admission of actors and charioteers to the Church, and the sacramental authority of the diaconate.