Can recommend : this book by Duff Cooper

“I don’t know how many biographies of Talleyrand there are in English and in French. I’ve read several in both languages over the years, but Duff Cooper achieved an extraordinary feat with this short book. It’s only about a hundred and fifty pages long. It brings Talleyrand completely to life and covers his own life, bringing out the person he was and the achievements he had to his credit (or, as some people would say, to his discredit). In a funny kind of way, Talleyrand has the same sort of problems with his personality and so on as Kissinger. There are some people who think he was a real scoundrel, and there are others who admire him greatly.” -

Michael Palliser, Diplomats & Former Diplomat