Bede, as he is now, was the most important source for the history of Christianity in England during the early medieval era. Bede was a strongly pro-Rome source and so he dates the "real" Christian Church in England (i.e. the one that had strong ties to the Roman Church) as beginning with the Gregorian mission (from 596CE). But Bede's work does make clear that Christianity existed in the British Isles before that mission, dating it from the conversion of Constantine onwards (so c.280 years of non Rome aligned Christianity in England), though he is very derogatory about it, and criticises it for not being more Rome aligned. Those in the English Reformation who wished to portray a historical continuity for the 'ecclesia Anglicana' used Bede's work to argue they were returning to Christianity as it existed in England before the Gregorian mission. So your average theologian/person education in church history in England at the start of the Reformation would have believed that an English Church aligned with Rome had existed for almost a thousand years.