The Christian Church was established in the British Isles well before 300. Some scholars believe that it was introduced by missionaries from the Eastern or Greek-speaking half of the Mediterranean world. Celtic Christianity had its own distinctive culture, and Greek scholarship flourished in Ireland for several centuries after it had died elsewhere in Western Europe.
However, in the fifth century Britain was invaded by non-Christian Germanic tribes: the Angles, Saxons, and Jutes. They conquered the native Celtic Christians (despite resistance by, among others, a leader whose story has come down to us, doubtless with some exaggeration, as that of King Arthur), or drove them north and west into Cornwall, Wales, Scotland, and Ireland. From these regions Celtic Christian missionaries returned to England to preach the Gospel to the heathen invaders. Meanwhile, the Bishop of Rome, Gregory the Great, decided to send missionaries from Rome, a group of monks led by their prior, Augustine (not to be confused with the more famous Augustine of Hippo). They arrived in Kent (the southeast corner of England) in 597, and the king, whose wife was a Christian, allowed them to settle and preach. Their preaching was outstandingly successful, the people were hungry for the Good News of salvation, and they made thousands of converts in a short time. In 601 the king himself was converted and baptised. Augustine was consecrated bishop and established his headquarters at Canterbury. From his day to the present, there has been an unbroken succession of archbishops of Canterbury.
In 603, he held a conference with the leaders of the already existing Christian congregations in Britain, but failed to reach an accomodation with them, largely due to his own tactlessness, and his insistence (contrary, it may be noted, to Gregory's explicit advice) on imposing Roman customs on a church long accustomed to its own traditions of worship. It is said that the British bishops, before going to meet Augustine, consulted a hermit with a reputation for wisdom and holiness, asking him, "Shall we accept this man as our leader, or not?" The hermit replied, "If, at your meeting, he rises to greet you, then accept him, but if he remains seated, then he is arrogant and unfit to lead, and you ought to reject him." Augustine, alas, remained seated. It took another sixty years before the breach was healed.
O Lord our God, who by thy Son Jesus Christ didst call thine Apostles and send them forth to preach the Gospel to the nations: We bless thy holy name for thy servant Augustine, first Archbishop of Canterbury, whose labors in propagating thy Church among the English people we commemorate today; and we pray that all whom thou dost call and send may do thy will, and bide thy time, and see thy glory; through Jesus Christ our Lord, who liveth and reigneth with thee and the Holy Spirit, one God, for ever and ever.
O Lord our God, who by your Son Jesus Christ called your Apostles and sent them forth to preach the Gospel to the nations: We bless your holy name for your servant Augustine, first Archbishop of Canterbury, whose labors in propagating your Church among the English people we commemorate today; and we pray that all whom you call and send may do your will, and bide your time, and see your glory; through Jesus Christ our Lord, who lives and reigns with you and the Holy Spirit, one God, for ever and ever.
Psalm 66:1-8 or 103:1-4,13-18
2 Corinthians 5:17-20a
Luke 5:1-11 (Ap)