I have just finished the last book in Mary Stewart's Merlin trilogy, The Last Enchantment. There is a follow-up novel, The Wicked Day, told from the point of view of Mordred. I haven't read this yet, but I have plans :-)
Admittedly, the only other Arthurian book I've read is The Mists of Avalon, by Marion Zimmer Bradley. So I don't know much- but what a FASCINATING subject! I truly, truly loved Mary Stewart's trilogy. It is amazing. It took me a while to actually pick the third book up, because I was not sure if I wanted to see the drama between Bedwyr (Lancelot), Arthur and Guinevere. But that part of the legend, thankfully, was very muted. And very realistic as well. The entire trilogy, actually, reads so realistically and so personally that you really *do* think it's Merlin talking about his life.
I still don't understand, though, how Guinevere could prefer a Lancelot-type character to an Arthur. Seriously- what was she thinking?! Though, to be fair, Lancelot never appeared in the original Arthurian tales. And the best part of the book was how those two had such a small role in it. Truly, the story was about Merlin and Arthur. Which is very interesting to note becaues so many times, with the Arthurian legends and myths, it's the Knights of the Round Table that take center-stage while Arthur kind of sits in the back and listens to their stories. So it was very good to read a story in which he, rightfully, takes center stage.
I think Arthurian legend is so interesting. Really- what a person, if he did exist. I wonder if he did- well, I think he did. But what was he really like, and how much is myth now? And what about Merlin? Was he real, too? Did he have magic? It's so interesting to look at Britain on the brink of becoming a Christian country because England, Ireland, Scotland and Wales just have so much HISTORY there before Christianity that it is so easy to believe in all the magic and the old gods that must have resided there before everything became monotheistic.
In Mary Stewart's Author's Note, she says that she hopes her trilogy will be a beginning for some people to get interested in King Arthur. I think it has certainly worked for me. I plan to delve more fully into the legend.