Geoffrey of Monmouth (1100-c1155) was one of the greatest, and most popular, of British authors - an indispensible link with our deep past - working from lost sources of written and oral history, and by inspiration and invention. Here is his account of the origins of Britain from his Latin 'best-seller' Histories of the King's of Britain:
BRITAIN, best of islands, lieth in the Western Ocean betwixt Gaul and Ireland, and containeth eight hundred miles in length and two hundred in breadth.
Whatsoever is fitting for the use of mortal men the island doth afford in unfailing plenty. For she aboundeth in metals of every kind; fields hath she, stretching far and wide, and hillsides meet for tillage of the best, whereon, by reason of the fruitfulness of the soil, the divers crops in their season do yield their harvests.
Forests also hath she filled with every manner of wild deer, in the glades whereof groweth grass that the cattle may find therein meet change of pasture, and flowers of many colours that do proffer their honey unto the bees that flit ever busily about them. Meadows hath she, set in pleasant places, green at the foot of misty mountains, wherein be sparkling well-springs clear and bright, flowing forth with a gentle whispering ripple in shining streams that sing sweet lullaby unto them that lie upon their banks.
Watered is she, moreover, by lakes and rivers wherein is much fish, and, besides the narrow sea of the Southern coast whereby men make voyage unto Gaul, by three noble rivers, Thames, to wit, Severn and Humber, the which she stretcheth forth as it were three arms whereby she taketh in the traffic from oversea brought hither from every land in her fleets.
By twice ten cities, moreover, and twice four, was she graced in days of old, whereof some with shattered walls in desolate places be now fallen into decay, whilst some, still whole, do contain churches of the saints with towers builded wondrous fair on high, wherein companies of religious, both men and women, do their service unto God after the traditions of the Christian faith.
Lastly, it is inhabited of five peoples, Romans, to wit, Britons, Saxons, Picts and Scots. Of these the Britons did first settle them therein from sea to sea before the others, until, by reason of their pride, divine vengeance did overtake them, and they yielded them unto the Picts and Saxons. Remaineth now for me to tell from whence they came and in what wise they did land upon our shores, as by way of foretaste of that which shall hereafter be related more at large.
…With the assent of his men, Brute returned to his fleet, and after loading his ships with all the treasures and luxuries he had acquired, he re-embarked, and with a prosperous wind sought out the promised island, where he landed at last in safety at Totnes.
At that time the name of the island was Albion, and of none was it inhabited save only of a few giants. Natheless the pleasant aspect of the land, with the abundance of fish in the rivers and deer in the choice forests thereof did fill Brute and his companions with no small desire that they should dwell therein.
Wherefore, after exploring certain districts of the land, they drove the giants they found to take refuge in the caverns of the mountains, and divided the country among them by lot according as the Duke made grant thereof. They begin to till the fields, and to build them houses in such sort that after a brief space ye might have thought it had been inhabited from time immemorial.
Then, at last, Brute calleth the island Britain, and his companions Britons, after his own name, for he was minded that his memory should be perpetuated in the derivation of the name.