“
The Fairy Story (or Folk-tale if you prefer that name) has at any rate been altered: for in this case it has been welded into the 'history'. And not, I think, for the first time by our poet. Beowulf and the Monster were already grafted onto the court of Heorot before ever he made this poem. But however it was done, by one poet or a succession of them, it caused great changes not only of detail but of tone. And it did not leave the history unaffected. You have only to consider how different is magic, faerie, and the like when it takes place in the court of Camelot in the time of Arthur, that are placed in history and geography, from a mere fairy-tale; and how different is the atmosphere of Arthur's court for all its atmosphere of 'history' because of this fairy-element, to understand what I mean.
”
”
J.R.R. Tolkien (Beowulf: A Translation and Commentary, together with Sellic Spell)