If there was a less cliched way to describe the Affair of the Diamond Necklace I would but it's simply a story you couldn't make up. A Jeanne La Motte, a countess who is a close confidant of Marie Antoinette, approaches Cardinal Rohan and asks him to purchase an expensive diamond necklace in the name of the queen. Rohan was only to eager to oblige as this meant he was back in favour with her. (Marie Antoinette strongly disliked him since he displeased her mother during his time at the Court of Vienna). He hoped that by helping the queen he would also help his own political ambitions.
However, things weren't that simple. Marie Antoinette didn't even know that Jeanne existed, let alone consider her a friend. She had never asked her to find somebody to purchase the necklace for her and had no interest in it.
Jeanne had taken advantage from the fact that Rohan was desperate to get back in favour with the queen and had spun a complex web of deceit around him. It involved countless forged letters, supposedly from Marie Antoinette and even a meeting between Rohan and the queen - played by a prostitute who looked a bit like her. Once Rohan had given the necklace to Jeanne she and her husband tried to sell the single diamonds.
Of course the jewelers noticed that no payment from the queen was forthcoming and the whole plot unraveled. As Jeanne hadn't been to subtle about her newfound wealth she was soon discovered and arrested. And so was Rohan - on the basis that nobody could be as stupid as he claimed to have been and so must have been a co-conspirator. But in the subsequent trial he was acquitted, while Jeanne and her husband were found guilty.
How to Ruin a Queen tells not only this story but also discusses the consequences the whole affair had. The court also found Marie Antoinette innocent from any knowledge of the plot but her hatred for Rohan was well-known. People suspected that she was behind the whole thing in an attempt to get rid of Rohan. Sympathies for the queen began to chill considerably afterwards and most historians assumed that without the affair the French Revolution might have ended less tragic for the French Royals.
Jonathan Beckman gives a good description of the affair itself but also doesn't forget to discuss the consequences. In less detail of course but enough to understand why it was such a big deal.
The book is well-researched, in so far this is possible. Obviously none of the people involved was too keen on keeping anything that might implicate them so many documents were destroyed.
That leaves the author with accounts from people that weren't directly involved (who also might not know the truth) or things like Jeanne's memoirs. In which she was also more than economical with the truth and tried very much to paint herself as a victim.
Beckmann does point that out and most of the time he puts them into perspective but on some occasions I found he was not clear enough on which claims were to be taken with a grain of salt and which might have been true.
Somewhere in the middle were also two chapters that didn't bring much new information. Instead they discussed Les Liaisons Dangereuses, Twelfth Night and The Marriage of Figaro and speculated on whether any of the people involved had read or seen them and match the characters from the stories with the real ones involved in the affair. If that was (at that length) really necessary is questionable but that doesn't take much away.
If you're interested in French history that book is definitely reccomended.