The Last Boleyn, Karen Harper
In short: There’s really no reason to read this if you’ve already read The Other Boleyn Girl. It was actually written before Gregory’s novel, and was originally published as Passion’s Reign (a much dopier title). The main differences are that The Last Boleyn gives us a lot more information on Mary’s early life, and that it suggests (in contrast to The Other Boleyn Girl) that Mary and William Stafford were together for years before they married. But it’s not nearly as much fun to read as Gregory’s novel, mostly because Stafford doesn’t seem like a very good option. He’s very much the smug, rich, noble, handsome, promiscuous hero that’s so popular in romance novels, even though the real William Stafford was a commoner. Harper’s Stafford is too busy stroking his own ego and sweeping Mary off her feet with his bulging biceps to be an appealing alternative to the smug, rich, noble, handsome, promiscuous jerks that populate Henry’s court. Gregory’s novel is better than this, and so is her Stafford.
Read it if you like: The Other Boleyn Girl. Or if you hated it and want to see what the alternative looks like.