Number 17 is The She-Wolf of France by Maurice Druon

Book number 5 in the Accursed Kings series, this one deals with the titular She-Wolf, Isabella, the only daughter of King Louis the Fair. Isabella, at the tender age of 12, was married off to Edward II of England. It was not a good match.

Edward II  was a weak king. Overfond of certain favourites, and perhaps homosexual, he quarreled with his barons nearly constantly, alienated his wife and ended up having to abdicate his throne to his son, who would become the very compentent and extremly war-like Edward III.

Most of the book concerns Isabella and her unhappiness. Her mistreatment at the hands of Edward's favourite pet, Hugh Despenser the Younger was enough that eventually she fled home to France and when she finally returned years later, it was at the head of an invasionary force, with her lover, the exiled baron Roger Mortimer.

Druon gives Isabella a good account, she is generally a strong woman, but her relationship with Mortimer is wrong, and she realizes enough that she is a hypocrite, but she also wants to finally be happy, and realizes that such a thing would never be possible with Edward. She is fortunate enough that her husband was a lousy king, so she wasn't the only one who wanted to be rid of him.

We also check in on the current King of France (the third of Isabella's brothers), Charles, another not strong ruler, who never forgives his sister for the part she played in the downfall of Charles' first wife, Blanche, and who basically spends his time letting his uncle of Valois rule (until Charles of Valois passes away) and hoping that his third wife will bear him a son.

Also of course, there is Guiccio, the young Lombard, who finally returns to France to see the son he has never before met. Of course though, he doesn't know that this isn't his son, but the rightful king of France, the son of Louis the Hutin. He is never told, but the wily Pope manages to worm the truth of Lord Bouville (pretty much only of the only, seemingly truly nice and good characters in these books), and learns of the Prince's existence.

The book ends with Edwards gruesome (and most probably not true) death. I liked this book a lot because, in dealing with England, it was more familiar territory for me, so I was able to 'place' when things were happening easier. With the death of Edward II and the soon to be ascension of Edward III, the Hundred Years War is bearing down on the French with frightening speed.