 Bede 's best @-@ known work is the Historia ecclesiastica gentis Anglorum , or An Ecclesiastical History of the English People , completed in about 731 . Bede was aided in writing this book by Albinus , abbot of St Augustine 's Abbey , Canterbury . The first of the five books begins with some geographical background , and then sketches the history of England , beginning with Caesar 's invasion in 55 BC . A brief account of Christianity in Roman Britain , including the martyrdom of St Alban , is followed by the story of Augustine 's mission to England in 597 , which brought Christianity to the Anglo @-@ Saxons . The second book begins with the death of Gregory the Great in 604 , and follows the further progress of Christianity in Kent and the first attempts to evangelise Northumbria . These ended in disaster when Penda , the pagan king of Mercia , killed the newly Christian Edwin of Northumbria at the Battle of Hatfield Chase in about 632 . The setback was temporary , and the third book recounts the growth of Christianity in Northumbria under kings Oswald of Northumbria and Oswy . The climax of the third book is the account of the Council of Whitby , traditionally seen as a major turning point in English history . The fourth book begins with the consecration of Theodore as Archbishop of Canterbury , and recounts Wilfrid 's efforts to bring Christianity to the kingdom of Sussex . The fifth book brings the story up to Bede 's day , and includes an account of missionary work in Frisia , and of the conflict with the British church over the correct dating of Easter . Bede wrote a preface for the work , in which he dedicates it to Ceolwulf , king of Northumbria . The preface mentions that Ceolwulf received an earlier draft of the book ; presumably Ceolwulf knew enough Latin to understand it , and he may even have been able to read it . The preface makes it clear that Ceolwulf had requested the earlier copy , and Bede had asked for Ceolwulf 's approval ; this correspondence with the king indicates that Bede 's monastery had excellent connections among the Northumbrian nobility . 
