Context: during the fall of the Roman Empire, many germanic peoples came to settle in roman lands, both through invasion and invitation. After central western roman authority collapsed, the now settled germanics created kingdoms of their own, most of which adopted many roman customs and institutions, to the point the romans in the Eastern Roman Empire took to calling them "latins".
However, presumably to the chaotic mists that surround the island of Avalon, this process of romanization never happened in the British Isles, and thus the people there became what we now know as "brits". #history