As you probably know, Jean Plaidy wrote a historical novel about Katherine Parr called The Sixth Wife. It's recently been reissued, both in the US and the UK. The UK cover is quite pretty.
Now comes another historical novel about Katherine Parr, this one by Suzannah Dunn (author of The Queen of Subtleties). The title? You guessed it: The Sixth Wife. To make matters worse, the UK covers are somewhat similar--although the Plaidy cover has a "headless woman" cover and the Dunn cover has a woman with her face turned away from the reader, they're each wearing ivory-colored dresses, and both have a script typeface.
Of course, it's quite common to see novels sharing the same title (Plaidy, Sharon Penman, and Juliet Dymoke all have novels called The Sun in Splendor, with variations in spelling), but one thinks that with the Plaidy book having been reissued, Dunn's publishers might have come up with a different title.
Plaidy novel-in-progress report: I'm reading The Pleasures of Love, about Catherine of Braganza, and am enjoying it very much. (By the way, if you do a search on Amazon USA for "The Pleasures of Love," be sure to put "Plaidy" in the search bar too, or be prepared to pull up all sorts of non-Plaidy items, and make sure that your boss isn't looking over your shoulder.)