Bede's Ecclesiastical History of England, ed. by A.M. Sellar, [1907], at sacred-texts.com
Augustine, thus strengthened by the encouragement of the blessed Father Gregory, returned to the work of the Word of God, with the servants of Christ who were with him, and arrived in Britain. The powerful Ethelbert was at that time king of Kent; he had extended his dominions as far as the boundary formed by the great river Humber, by which the Southern Saxons are divided from the Northern. On the east of Kent is the large Isle of Thanet, containing, according to the English way of reckoning, 600 families, divided from the mainland by the river Wantsum, which is about three furlongs in breadth, and which can be crossed only in two places; for at both ends it runs into the sea. On this island landed the servant of the Lord, Augustine, and his companions, being, as is reported, nearly forty men. They had obtained, by order of the blessed Pope Gregory, interpreters of the nation of the Franks, and sending to Ethelbert, signified that they were come from Rome, and brought a joyful message, which most undoubtedly assured to those that hearkened to it everlasting joys in heaven, and a kingdom that would never end, with the living and true God. The king hearing this, gave orders that they, should stay in the island where they had landed, and be furnished with necessaries, till he should consider what to do with them. For he had before heard of the Christian religion, having a Christian wife of the royal family of the Franks, called Bertha; whom he had received from her parents, upon condition that she should be permitted to preserve inviolate the rites of her religion with the Bishop Liudhard, who was sent with her to support her in the faith. Some days after, the king came into the island, and sitting in the open air, ordered Augustine and his companions to come and hold a conference with him. For he had taken precaution that they should not come to him in any house, lest, by so coming, according to an ancient superstition, if they practised any magical arts, they might impose upon him, and so get the better of him. But they came endued with Divine, not with magic power, bearing a silver cross for their banner, and the image of our Lord and Saviour painted on a board; and chanting litanies, they offered up their prayers to the Lord for the eternal salvation both of themselves and of those to whom and for whom they had come. When they had sat down, in obedience to the king’s commands, and preached to him and his attendants there present the Word of life, the king answered thus: "Your words and promises are fair, but because they are new to us, and of uncertain import, I cannot consent to them so far as to forsake that which I have so long observed with the whole English nation. But because you are come from far as strangers into my kingdom, and, as I conceive, are desirous to impart to us those things which you believe to be true, and most beneficial, we desire not to harm you, but will give you favourable entertainment, and take care to supply you with all things necessary to your sustenance; nor do we forbid you to preach and gain as many as you can to your religion." Accordingly he gave them an abode in the city of Canterbury, which was the metropolis of all his dominions, and, as he had promised, besides supplying them with sustenance, did not refuse them liberty to preach. It is told that, as they drew near to the city, after their manner, with the holy cross, and the image of our sovereign Lord and King, Jesus Christ, they sang in concert this litany: "We beseech thee, Lord, for Thy great mercy, that Thy wrath and anger be turned away from this city, and from Thy holy house, for we have sinned. Hallelujah."