I was recently sharing this book with a friend, and came to "The Young King of the Black Isles".
Here is an excerpt which greatly excited my curiousity:
"You must know, sire, that my father was Mahmoud, the king of this country, the Black Isles, so called from four little mountains which were once islands, while the capital was the place where now the great lake lies."
This immediately made me think of Thera. I wonder where else there may be references to the Black Isles in ancient documents, and if these are known to be another set of islands, perhaps in the Red Sea or Arabian Sea...