Six Wives is not historical fiction, but purports itself to be “a study” of the history of these people.
The challenge is that after each wife was dead, Henry VIII and his aides obliterated the actual history of the women, so it’s hard to reconstruct that history.
The book is an interesting read. But, if you’re looking for an in-depth look at the wives — their personalities, their thoughts, etc. — this is not the book for you.
If you’re interested in an in-depth look at The Great Matter and what lead Henry VII to split away from the Catholic Church, this book does a pretty amazing job at that.