In the course of researching Gog-Magog I looked at legends and tales of giants. I restricted myself to stories from England and Wales, although - or more likely because - giant legends exist across the world, back to antiquity, before gods, before floods, before what is called civilisation.
In the course of this research I came across the story of Gwenhafyr, more commonly known by her Latinate name of Guinnevere. It is one of many hundreds of tales around King Arthur and his knights, and one of many overlaps between giant myths and Arthurian legend. Most of these involve a knight proving his valour by slaughtering a fearsome ogre and stealing his daughter whether she wants him or not.
Malory's version of Arthur's betrothal to Gwen is, to be frank, very undramatic in which she has no agency. It is most notable for her father, a neighbouring king, returning to Arthur something that had once belonged to his father Uther: a table, a larger circular table...
The story I came across has Gwen as the daughter of a Welsh giant. Arthur "wins" her (plot spoiler!) but not by violence. It has magic and intrigue, and calls on a tumultuous backstory of murder and curses. More importantly, while Malory paints Gwen as faithless backstabbing bitch from hell, this one offers some kind of explanation for her later betrayal of Arthur which leads to his downfall and death.
I thought it was worth telling her tale from her own point of view, so I've produced a standalone 18-page booklet of the tale, which I'm adding as a free Easter egg to every order of Gog-Magog.