Wasn't that also the time of Camelot and King Arthur? A comet crashed into Brittain starting the black plague all over Europe.

sometimes whole civilizations being eradicated, by impacts of debris from the sky.” Could something cataclysmic have happened in the age of Arthur that was not properly recorded at the time? Has this later been ‘mythologized’ to create the figure we today know as Arthur, and all the stories that come with him?

[link to atlantisrisingmagazine.com]