The latest from biographer Anne Sebba, That Woman: The Life of Wallis Simpson, Duchess of Windsor, makes its American debut courtesy of St. Martin’s. Already a bestseller in the UK, it takes a fresh look at the American divorcee for whom Prince Edward abdicated the throne, a woman who continues to both fascinate and revile, with extensive research and the help of a newly discovered cache of letters from Wallis to one of the husbands she left behind. Tip Sheet braved the five-hour time difference to speak with Sebba in London.

What is it about Wallis Simpson that continues to captivate, not just in the U.K. but around the world?

I think it’s because she’s elusive, people can’t pin her down. What was it about this middle-aged woman, who to most people wasn’t particularly beautiful or well-educated or rich, who lacked the obvious sort of peaches-and-cream look of an English rose. What was it that enabled her to capture a prince’s heart? To demand such total love? Because if they only knew that secret, they too could capture a prince! The difference with my book is that I don’t look at her to explain it—I look at the man. Once you turn the tables on that, take a look at him, it suddenly becomes much clearer.

So it turns out Edward was no Prince Charming?

Well I think he was early on, he was devastatingly good looking and charming, but by his mid-to-late 30s, he’d lost some of that glamour. This was a time when the royal family wasn’t interviewed, people didn’t know what was behind the face and the smile. What you find there is a very troubled adolescent, who threatened suicide in another relationship, and who didn’t really want to be king—unless he could be king under his terms, whatever those vaguely-defined terms were. When we went off to war, he said “What does it matter if I get killed? There’s two other brothers who could take my place.” He lacked intellectual depth and understanding, and I think at some level he knew he wasn’t especially suited to the monarchy, didn’t have the frame of mind that said duty and responsibility are what really matters.

In the Telegraph, Roger Lewis says you make the case that Wallis Simpson saved the U.K. from the reign of a Nazi sympathizer. Do you see Wallis as a kind of unsung British hero?

Yes, an unsung heroine is one way of looking at her. It’s a bit of a stretch to say she saved the country from Nazi domination, but actually we got a much better monarch [in King George VI], more suited to the critical times ahead, a monarch who was prepared to take the advice of his ministers.

And ordinary people could indentify with George VI and Elizabeth, with their terribly photogenic children, in ways they just couldn’t with Wallis. The women of England were terrified of her, they demonized her, because at a time when divorce in England was so rare and expensive, to have this woman who was twice divorced with two living ex-husbands—women were really terrified what the future might be if she became queen. Our husbands will all leave us! We’ll be left alone to raise the children! Terrible woes will face the country if we allow this woman to be queen!

Rumors of Wallis’s sex life are legion—including aggressiveness and Chinese sex tricks, hermaphroditic biology, clandestine threesomes in Hollywood. Could Edward have been in the thrall of a sexual predator?

Those rumors have been out there and I didn’t think you could write a book without dealing with them. So I’ve spoken to a lot of doctors and psychologists trying to understand. There’s no question that her personality fits the possibility [of hermaphroditic biology], and there are quotes from a number of her contemporaries who all thought she looked masculine, but of course it doesn’t prove anything. Short of exhuming her and doing a DNA test, we’ll never know.

People are so baffled by what her secret was that they throw all these things into the mix trying to explain her, and I don’t think you need to do that. A better explanation is that they found a mirror image of each other. I actually think the relationship was not based on sex, there was more a psychological need in Edward than a sexual need.

Do you think Wallis was happy?

No. You can look at one of those final interviews, a few years before Edward died. When asked if they’ve been happy, Wallis jumps in to answer, nervous, fiddling with her bouffant hair, “Oh well I’ve got a few regrets. Who doesn’t? But it’s all fine.” And Edward reaches out and takes her hand and answers, “Of course we’ve been happy.” It wasn’t what she planned at all. I don’t believe she ever wanted to be queen, but she didn’t want to be married to an ex-king, either.

Having found this new material, this extraordinary archive of letters form Wallis to [second ex-husband] Ernest Simpson makes it clear that Ernest was really the deep love of her life. I don’t see a passionate, lustful love, but she realized too late what she was losing by giving him up, and I think that’s the other really new twist on the whole thing: she never expected Edward would abdicate, that it would go to that extreme. Everyone wants to look at the sex, but I really don’t think that’s the explanation—this is the psychological story of a troubled man who meets an adventurous woman, and it went too far.