Bede's Ecclesiastical History of England, ed. by A.M. Sellar, , at sacred-texts.com
AT this time the nation of the Northumbrians, that is, the English tribe dwelling on the north side of the river Humber, with their king, Edwin, received the Word of faith through the preaching of Paulinus, of whom we have before spoken. This king, as an earnest of his reception of the faith, and his share in the heavenly kingdom, received an increase also of his temporal realm, for he reduced under his dominion all the parts of Britain that were provinces either of the English,
or of the Britons, a thing which no English king had ever done before; and he even subjected to the English the Mevanian islands, as has been said above. The more important of these, which is to the southward, is the larger in extent, and more fruitful, containing nine hundred and sixty families, according to the English computation; the other contains above three hundred.
The occasion of this nation's reception of the faith was the alliance by marriage of their aforesaid king with the kings of Kent, for he had taken to wife Ethelberg, otherwise called Tata, (a term of endearment) daughter to King Ethelbert. When he first sent ambassadors to ask her in marriage of her brother Eadbald, who then reigned in Kent, he received the answer, "That it was not lawful to give a Christian maiden in marriage to a pagan husband, lest the faith and the mysteries of the heavenly King should be profaned by her union with a king that was altogether a stranger to the worship of the true God." This answer being brought to Edwin by his messengers, he promised that he would in no manner act in opposition to the Christian faith, which the maiden professed; but would give leave to her, and all that went with her, men and women, bishops and clergy, to follow their faith and worship after the custom of the Christians. Nor did he refuse to accept that religion himself, if, being examined by wise men, it should be found more holy and more worthy of God.
So the maiden was promised, and sent to Edwin, and in accordance with the agreement, Paulinus, a man beloved of God, was ordained bishop, to go with her, and by daily exhortations, and celebrating the heavenly Mysteries, to confirm her, and her company, lest they should be corrupted by intercourse with the pagans. Paulinus was ordained bishop by the Archbishop Justus, on the 21st day of July, in the year of our Lord 625, and so came to King Edwin with the aforesaid maiden as an attendant on their union in the flesh. But his mind was wholly bent upon calling the nation to which he was sent to the knowledge of truth; according to the words of the Apostle, "To espouse her to the one true Husband, that he might present her as a chaste virgin to Christ."' Being come into that province, he laboured much, not only to retain those that went with him, by the help of God, that they should not abandon the faith, but, if haply he might, to convert some of the pagans to the grace of the faith by his preaching. But, as the Apostle says, though he laboured long in the Word, "The god of this world blinded the minds of them that believed not, lest the light of the glorious Gospel of Christ should shine unto them."
The next year there came into the province one called Eumer, sent by the king of the West-Saxons, whose name was Cuichelm,to lie in wait for King Edwin, in hopes at once to deprive him of his kingdom and his life. He had a two-edged dagger, dipped in poison, to the end that, if the wound inflicted by the weapon did not avail to kill the king, it might be aided by the deadly venom. He came to the king on the first day of the Easter festival,' at the river Derwent, where there was then a royal township, and being admitted as if to deliver a message from his master, whilst unfolding in cunning words his pretended embassy, he startled up on a sudden, and unsheathing the dagger under his garment, assaulted the king. When Lilla, the king's most devoted servant, saw this, having no buckler at hand to protect the king from death, he at once interposed his own body to receive the blow; but the enemy struck home with such force, that he wounded the king through the body of the slaughtered thegn. Being then attacked on all sides with swords, in the confusion he also slew impiously with his dagger another of the thegns, whose name was Forthhere.
On that same holy Easter night, the queen had brought forth to the king a daughter, called Eanfled. The king, in the presence of Bishop Paulinus, gave thanks to his gods for the birth of his daughter; and the bishop, on his part, began to give thanks to Christ, and to tell the king, that by his prayers to Him he had obtained that the queen should bring forth the child in safety, and without grievous pain. The king, delighted with his words, promised, that if God would grant him life and victory over the king by whom the murderer who had wounded him had been sent, he would renounce his idols, and serve Christ; and as a pledge that he would perform his promise, he delivered up that same daughter to Bishop Paulinus, to be consecrated to Christ. She was the first to be baptized of the nation of the Northumbrians, and she received Baptism on the holy day of Pentecost, along with eleven others of her house. At that time, the king, being recovered of the wound which he had received, raised an army and marched against the nation of the West-Saxons; and engaging in war, either slew or received in surrender all those of whom he learned that they had conspired to murder him. So he returned victorious into his own country, but he would not immediately and unadvisedly embrace the mysteries of the Christian faith, though he no longer worshipped idols, ever since he made the promise that he would serve Christ; but first took heed earnestly to be instructed at leisure by the venerable Paulinus, in the knowledge of faith, and to confer with such as he knew to be the wisest of his chief men, inquiring what they thought was fittest to be done in that case. And being a man of great natural sagacity, he often sat alone by himself a long time in silence, deliberating in the depths of his heart how he should proceed, and to which religion he should adhere.