I took the change-of-era things to be the coming rise of Islam, and felt very clever for noticing => , so I didn't catch hints in this direction at _all_.

(I have been fighting off the urge to re-read, because I just don't have time; I was proud of my willpower, that I managed to just check a couple of details last night and not re-read the entire ending. Besides, hey, new book really soon now!)