Monmouth Rebellion fiction 'The Royal Changeling'

It's been a fairly fertile ground for fiction, the West Country rising of 1685. There's been a lot - Conan Doyle's Micah Clark and classics like Blackmore's Lorna Doone have been set against these turbulent times and many many more. This novel is different in that it is in the fantasy genre and very good it is too. I normally hate fantasy but this was different.
I met the author John Whitbourn at one of our reenactments and he gave me a copy of this book and it is quite fascinating. He also wrote for our 1685 society journal The So-Ho gazette a true story of someone offering Monmouth a multi-barrelled gun on the eve of Sedgemoor which was sadly turned down.
(Monmouth's Stalin Organs - or Ingenious Inventions and Annoying Authors) The So-ho Gazette - Newsletter of the 1685 Society July 2000.
Anyway the plot of the Royal Changeling is
Invading England after Charles II's death, the Duke of Monmouth comes face-to-face with an old friend -- Theophilus Oglethorpe. Oglethorpe, in common with only a handful of others, knows Monmouth's background fully -- not only that he is Charles's son, but also that he has elven blood, and has allied himself with evil powers in order to take England's crown. In fact, he is being used as a cat's paw by one far more steeped in evil than himself...King Arthur, who would return to rule Britain and the entire world. Through London, Glastonbury, Sedgemoor, and many stranger places, unearthly battles rage, and the elves forsake their millennia-long neutrality... John Whitbourn's new novel fascinates with its grand sweep of war and intrigue, truth and fantasy. His characters have all the qualities and faults of Tolkien's heroes and villains, and yet they live and breathe in seventeenth-century England. With The Royal Changeling, Whitbourn shows himself to be a master of fantastic literature.