I've spent the week reading Napoleon's Master: A Life of Prince Talleyrand (David Lawday, 2007).
Anyone who lived in France between 1754 and 1838 lived in interesting times; Talleyrand was an aristocratic diplomat who shaped them. He was a consummate survivor who was managed to hold high positions under Louis XVI, various Revolutionary governments, Napoleon, and the restored monarchy. Not surprisingly, he was accused of being a self-serving turncoat, but Lawday presents him as a man who had both personal ambition and a genuine desire to promote the good of France, and ultimately of all Europe, even if that meant betraying the current government of France. (He definitely gave intelligence to Napoleon's enemies after concluding that the emperor's hunger for conquest could never be sated and would end in France's ruin.) I'm not sure he was quite as principled as Lawday paints him--but, then, Wellington defended him on much the same terms, and I tend to trust Wellington's character judgments.
The biography is an enjoyable read, chatty and full of anecdotes. I especially liked the story of a dinner Talleyrand hosted at the Congress of Vienna, where the various ambassadors and princelings got into a good-natured argument about which was the finest cheese of all--Castlereagh lauding Stilton, etc. Talleyrand just listened until a valet came in and whispered to him that a shipment of supplies had just arrived from France. He gave an order, and his servants brought in the brie. "Gentleman, I present the winner," he announced.
All in all, an informative ramble through a turbulent life.