Inventing Elsa Maxwell by Sam Staggs is a new biography of an American who rose from humble roots to become a famous party hostess. She popularized scavenger hunts and treasure hunts, wrote a gossip column, and even appeared in movies.
Maxwell developed real friendships with the rich and famous, including royalty. The book includes chapters on the Duke and Duchess of Windsor and Princess Margaret. It's scheduled to be published in the U.S. later this month and in the U.K. next month. Looks like a good read.
Thank you to Katie Bassel at St. Martin's Press for letting me know about this book!