To be honest I wasn't keen on the writer's style. That of course is subjective. However I'm uncertain of the author's assertion that Diane de Poitiers "hated sex." If only because it's impossible to determine that about a person dead for 500yrs.
Robert Knecht was one of my lecturers whilst I was doing my history degree. Unfortunately, ex-students don't get a discount on his books, and I can't afford them either. And I think I annoyed him by preferring the Russian and Austrian elements of the European history modules to the French modules.
Catherine de Medici was referred to as The Serpent Queen.
Francois Hercule, Duke of Alencon (1555-1584) was the youngest son of King Henry II of France and Catherine de' Medici.
http://www.maryevans.com/history/10467398