Yeah I was wondering about this as well. To what extent were the greek myths known in that part of the world at that time? A brief googling suggests that from the 6th century onward there were various transcriptions of greek texts (Boethius, for example), but it's not 100% clear to me what was known / available in Britain in the 10th century, specifically.

Apparently Irish monks preserved some ancient Greek texts after the collapse of Rome. Interesting stuff!