This is an intelligent novel and one with an unusual love story at its centre: that between a 50 year old ex-African prince, ex-slave, now a scholar in C17th Netherlands, and the 40-something Elizabeth of Bohemia, daughter of James 1, sister of Charles 1, and widow of the Elector Palatine. However the story itself seems de-centred, and lacks a clear narrative pull to hold it together.
The first third focuses on Pelagius and his relationship with his ex-owner who free him and now uses him as his assistant in the work he is writing on Eastern flora. While there is much interest in the printing and publishing trade of the time, and some interesting sidelights on the characters and relationship between the two men, this reads like a prologue before the story really gets going: we keep wondering why this is all important.
The story-line of the relationship between Pelagius and Elizabeth seems very artificial: there's no sense of any social, racial, cultural gap between them, and the transition from friendship and affection to passionate love is an uncomfortbale one for me since we never see this developing. There is a hunt where Elizabeth rides a horse called Dido which flags up Stevenson's debt to Vergil's Aeneid, and while the marriage isn't consummated in a cave and has the authorisation of some of the court, the ending is still a bleak one.
The last third seems to drift loose from what has gone before with much more of a concentration on European politics.
For me, there was very little sense of the C17th although that may be because the Netherlands are much less of a known setting.
So overall I think this is an intelligent book (as we would expect it would be written by an English professor) which takes an interesting idea but doesn't manage to make me care about either the story or the characters. I finished the book and put it down - and that's it. A book that engages the head, I think, far more than the heart.