After six years of uncertainty following the end of the war, Wallis still felt rootless and “homeless on the face of the earth.” The Windsors rented and borrowed houses until there could be no possible doubt that returning to England was out of the question. It was Wallis who finally recognized that there would never be meaningful work offered to the duke and that they would never be able to make their home in England. She had always shown remarkable self-awareness of her own shortcomings, even if she was unable to change them, and now she tried to give the duke some of the courage she was scraping together as he, often depressed or ill, faced a still-hostile family and an ever colder world.

Their first trip to England together in the fall of 1946 was a disaster. They stayed with their friends the Earl and Countess of Dudley at Ednam Lodge. On Oct. 16 a burglar broke into the house and stole Wallis’s jewelry, which she had left unsecured when they went out for the evening. Wallis was distraught; the jewelry had defined her romance with the then prince and given her security. An exotic bird of paradise brooch, with a cabochon sapphire breast and a plumage of diamonds, had just been made for her by Cartier that year. She never saw it, or any of the other stolen pieces, again.

The household was in turmoil, as police taking fingerprints jostled with reporters seeking interviews. The quiet visit with a minimum of publicity that they had promised an “unrelenting royal family” was now splashed all over the press. In a country hard hit by postwar austerity, discussion of such a fabulous haul of jewelry (estimated by the Windsors at $80,000) elicited little sympathy. According to Lady Dudley, Wallis in the hours after the robbery showed “an unpleasant and to me unexpected side of her character. . . . She wanted all the servants put through a kind of third degree. But I would have none of this, all of them except for one kitchen maid being old and devoted staff of longstanding. . . . The duke was both demented with worry and near to tears.”

The next day there was another drama. Before going out for a stroll, Wallis, according to Laura Dudley, who told the story in her memoirs, asked the duke to put away a small brooch of sapphires and rubies with their entwined initials and an inscription, “God Bless WE Wallis,” which had been an early gift in 1935 and had eluded the burglars only because she had been wearing it. When they returned from the walk, he could not remember where he had put it. “We stayed up most of the night; he obviously feared to go to bed empty-handed. At about 5 a.m. by some miracle we found it, under a china ornament. Never have I seen a man so relieved.”

Corbis/Bettmann

The duke never gave up trying to rectify that which had been denied his wife. Insurance money helped him to start a new jewelry collection for her, and in April 1949 he again consulted Viscount Jowitt for a legal opinion on the question of her title. In 1937 the then Sir William Jowitt based his opinion on the view that “he became ‘His Royal Highness’ not by virtue of any letters patent but for the simple reason that he was the son of his father, who was the sovereign of this country.” He went on to declare “that the Duchess of Windsor is, by virtue of her membership of the royal family, entitled in the same way as other royal duchesses to be known by the style and title of ‘Her Royal Highness.’ ” Yet while insisting that it was simply a matter of good manners, he nonetheless pointed out that the situation could be reversed only by fresh letters patent, and since the king would not issue these, the Windsors remained permanent, half-royal exiles — arguably the desired effect.

Notwithstanding this, their staff in France, 30 in all spread between two houses, learned to refer to her as “Son Altesse Royale” (perhaps S.A.R. sounded less threatening than H.R.H. and certainly fell into the category of “good manners”), footmen wore royal livery, and Wallis’s notepaper had a small crown above a “W.” And the British royal family could not prevent the duke from buying Wallis jewels fit for a royal highness. The duke had visited Cartier in Paris just before the fall of France with pocketfuls of stones, some of Wallis’s bracelets and a necklace, together with instructions to make up at least one piece, apparently oblivious to the notion that producing such a jewel in wartime might strike some as insensitive. The bold diamond flamingo clip, with startling tail feathers of rubies, sapphires and emeralds, was made in 1940 with retractable legs so that Wallis could wear it centered without a leg digging into her chest if she bent down. Where clothes or jewels were concerned, she was never fearful. She had some magnificent jeweled compacts “and was always making up at table, which of course is very sexy,” according to the society decorator Nicholas Haslam.

Horst/©Condé Nast Archive/Corbis

By 1952 the Windsors had reached a decision about where they should base themselves: France. They would live informally at the Mill, a house they bought at Gif-sur-Yvette, 45 minutes outside Paris to the south of Versailles, and the only house after the war that they owned, and in formal splendor in Paris itself at a house in the Bois de Boulogne, 4 Rue du Champ d’Entraînement, loaned to them for a peppercorn rent by the City of Paris. It was Wallis who arranged their décor, making sure the town house appeared as imposing as possible for a building that was not an actual palace. In the drawing room hung a portrait of Queen Mary, the mother-in-law who would never agree to meet her, as well as one of the duke, equally resplendent in Garter robes. His red and gold silk banner, with coat of arms, hung over the marble entrance hall, where other royal memorabilia was also displayed.

Just as the Windsors were deeply involved in expensively refurbishing both houses, the duke’s brother, George VI, died, at 56, in February 1952. A heavy smoker, he had been suffering from lung cancer. But the perception now hardened that somehow the premature death had been Wallis’s fault, as the burdens of state, for which he had not been groomed, hastened his death. The duke went to the funeral alone. The accession of the duke’s 25-year-old niece, Queen Elizabeth II, was to make little difference to the Windsors’ standing in the eyes of the royal family, even though Elizabeth had been a child at the time of the abdication. But with the king’s death went the personal allowance from him agreed to at the time of the abdication. “They are beasts to continue to treat you the way they do . . . I am afraid Mrs. Temple Sr. [the queen mother, whose elder daughter they had nicknamed Shirley Temple] will never give in,” Wallis wrote to the duke, who, in reply, told her that while some court officials were friendly and correct on the surface, there was “only granite below.”

Wherever the Windsors lived — and they also retained Suite 28A in New York’s Waldorf-Astoria — they were both locked in stasis. There were a few new friends providing an occasional shot of circulating blood. But most of their visitors wanted to talk about the past. Every day was lived in the shadow of 1936, with no way to move forward as money worries, illness and bitterness against the royal family all competed for attention.

Such new activity as they embarked on inevitably evolved around reliving the old. The duke was, almost as soon as peace descended in Europe, approached to write his memoirs. He started by writing a series of articles for Life, helped by the former Reuters journalist Charles J. V. Murphy, then a staff writer on the magazine. The collaboration was stormy almost from the outset because Wallis disliked Murphy. But the money was useful, and the duke described Murphy as “a good egg and quite brilliant journalist.” Life was pleased with the result, which led to a lucrative book and later to the documentary “A King’s Story.” It also led to Wallis herself writing her memoirs, “The Heart Has Its Reasons.”

Horst/Vogue/Condé Nast Archive. Copyright © Condé Nast. A portrait of Wallis’s disapproving mother-in-law, Queen Mary, hung in the Windsors’ Paris living room.

In spite of their earlier differences, she too tried to work with Murphy. When that arrangement broke down in disagreement, she hired the American author Cleveland Amory, but he, too, was not as pliable as she wished. When he withdrew, she decided to complete the manuscript herself. But she needed time on her own for this, undistracted by the duke’s undiminished and constant need for her. She went off to the Mill, alone, to do the finishing touches, and the book was published in 1956 by Houghton Mifflin. In spite of much that was obscured or omitted, many were surprised by how much of Wallis’s personality it revealed.

Charles Pick, the publisher, had several meetings with the duchess, whom he described as “a rather brittle, hard and vain person.” Having been warned in advance by the Foreign Office not to refer to her as Her Royal Highness, he was on his guard when they first met. She was, he recalled, lying on a chaise longue, with a large box of Charbonnel et Walker chocolates within reach. “As she rose to greet me, her opening remark was: ‘Can you tell me who Marilyn Monroe’s publicity agent is? I have all the newspapers each day, and I was generally on the front page. But now I see that Marilyn Monroe is. . . . Well, somebody has pushed me off.’ ”

Elsa Maxwell, the gossip columnist and party hostess who got to know Wallis after the war, had a very public falling out with her partly in connection with jealousy over Marilyn Monroe stealing headlines. They eventually reconciled, but not before Maxwell previewed “The Heart Has Its Reasons,” pointing out that the duchess “seeks to compensate for all she hoped for and lost with an almost feverish pursuit of pleasure. . . . Many of the things she has done in this search, largely because of the high-handed, selfish way in which she has done them, have contributed to her final frustration — the fact that the Windsors’ prestige is not what it used to be and the Windsors’ romantic aura is sadly diminished.”

In March 1953, the duke’s mother, Queen Mary, died. Again the duke went, alone, to England for the funeral, bitterly aware of all the pain that his mother’s refusal ever to accept Wallis as her daughter-in-law had caused and desolate that the acceptance he craved for his decision to marry Wallis had been withheld until the end. “My sadness was mixed with incredulity,” he famously wrote to Wallis, “that any mother could have been so hard and cruel toward her eldest son for so many years. . . . I’m afraid the fluids in her veins have always been as icy cold as they are now in death.” Wallis wrote to him while he was away like a fussing mother: “Please eat and take care of yourself. . . . Don’t fetch and carry for everyone, including servants.” But she also begged him to “Work [for the restoration of the allowance] on Cookie [the queen mother] and Shirley [Temple, that is, the new queen].”

With or without the allowance, Wallis and her team of decorators went ahead with plans to make 4 Rue du Champ d’Entraînement as regal as possible. Yet in spite of the Windsors’ beautifully appointed home and fine cuisine, the number of important and interesting people who sought them out rapidly diminished. Wallis did little to conceal her fury that the brilliant court of statesmen and artists — glimpsed for just a few tantalizing months in 1936 — had evaporated. The Mill, in contrast, was neither magnificent nor particularly elegant. Diana Mosley (nee Mitford), wife of the British Fascist leader Sir Oswald Mosley, who became a close friend in the 1950s, was critical of the rather garish décor. “It was very bright with patterned carpets, lots of apricot and really more Palm Beach than English or French.” Cecil Beaton called the Mill “overdone and chichi . . . medallions on the walls, gimmicky pouffs, bamboo chairs. Simply not good enough.” And the American decorator Billy Baldwin was even more dismissive: “Most of the Mill was awfully tacky, but that’s what Wallis had — tacky Southern taste, much too overdone, much too elaborate and no real charm.”

Both the Windsors were keen collectors, and Wallis’s taste — a kind of cluttered vulgarity — was left unfettered by decorators at the Mill. But as most of their entertaining was done in the city, only their closest friends saw this. Wallis always preferred town life, while the duke was happiest at the Mill and took up gardening again, which had once given him so much pleasure. Susan Mary Patten, wife of an American diplomat, described the problem: “I never saw a man so bored. He said to me: ‘You know what my day was today? . . . I got up late and then I went with the duchess and watched her buy a hat and then on the way home I had the car drop me off in the Bois to watch some of your American soldiers playing football and then I had planned to take a walk but it was so cold that I could hardly bear it. In fact I was afraid that I would be struck with cold in the way people are struck with heat, so I came straight home. . . . When I got home, the duchess was having her French lesson, so I had no one to talk to. . . .”

Courtesy of Sotheby’s

By the mid-1950s the Windsors had established a routine. In addition to their two French homes, they would spend three months in America and summer with friends or go somewhere warm like Biarritz, which became a favorite destination for a while, or Spain. But whether in Paris or in New York, their life varied little, consisting of shopping, formal dinners and answering occasional demands to be patrons of a charity. What jewels he was buying, what clothes she wore, how her hair was coiffed or her makeup applied was still a regular source of newspaper interest, which pleased her as she tried to regain some control over her circumstances and environment. This was the only way she knew to keep her many fears and phobias at bay, and neither a hair on her head nor a cushion on her sofa was allowed to be out of place. Her sheets were ironed every night, and the water in her vases was always crystal clear. The one exception in this highly regulated universe was the freedom allowed their scarcely house-trained pugs — Trooper, Disraeli and Diamond were the favorites — who, lavished with attention, ate from silver bowls and were rarely reprimanded whatever they did inside or out.

Wallis sometimes wore a tiny gold notebook on a chain around her wrist and would use it to write down instructions. According to some stories, she would dab face powder on the walls and demand that her decorators match the color. Her rules for living were widely quoted — “If you can afford it, then there is no pleasure in buying it,” or “You cannot be too rich or too thin” — apocryphal, perhaps, but it was how she talked. Those who admired her, like Nicky Haslam, found her quick wit refreshing. He recounted how in 1960, when the engagement of Princess Margaret Rose to Antony Armstrong Jones was announced, the duchess quipped that these days, “She’s dropped the Rose and picked up the pansy.”

Her desire to be thin took on a new urgency. Breakfast for both of them was grapefruit juice and black tea, and lunch perhaps one egg or, for the duke, one piece of fruit. She gave her chef written instructions about the weight of her portion of grilled meat: 190 to 200 grams, no more. And it was quickly noted by hostesses that even tiny portions were mostly just pushed around her plate while she talked. She understood the need to be in command of her image and generally had a surer touch with clothes than décor. Nonetheless, her craving to be first with the latest fashion led to a few ghastly faux pas like sequined hot pants on one occasion and a Paco Rabanne spacesuit on another. But mostly she was impeccably chic, choosing plain clothes better to show off her enormous jewels and short skirts to show off her (relatively) good legs. Still, stories circulated about how her multiple face-lifts had left her with eyes that wouldn’t close even when she was asleep.

Frank Giles, the Times of London correspondent in Paris in the 1950s, was invited to dinner: “It was a large dinner party, rather unsavory characters . . . sort of blue rinse American widows and jet-setting Europeans and hangers-on. I thought the atmosphere was not very nice. But a very good dinner.” Giles recalled the duke discussing Prime Minister Anthony Eden as “ ‘a bad man, a hopeless man . . . he helped precipitate the war through his treatment of Mussolini . . . that’s what he did, he helped to bring on the war . . . pause . . . and of course Roosevelt and the Jews. . . .’ When he was not making remarks about the Jews he could be charming.”

Occasionally, Wallis went too far, disgracing the duke in public. Kenneth de Courcy, a onetime confidant, recalled a dinner in Cannes when a new golf course was being built: Wallis was sitting quite a ways from the duke, who was next to the wife of the British consul talking about the course. “Suddenly, in front of 40 people, the duchess yelled across the table, ‘Oh, do stop talking nonsense, David, you know nothing whatever about golf courses, do stop lecturing that woman.’ I lost my cool and said, ‘If I may say so, His Royal Highness presided over one of the greatest real estate concerns in the world, the Duchy of Cornwall, and knows all about golf courses and property.’ She piped down at once.”

Much more shocking was Wallis’s flirtation with Jimmy Donahue, the millionaire homosexual playboy and heir to the Woolworth fortune whom the Windsors first met in 1947. Wallis, often restless and bored, was intrigued by his salacious conversation. The Windsors and Donahue became a well-known threesome for a while, even though many in society were scandalized. “There can be no doubt of the duchess’s preference for gay men,” wrote her biographer Michael Bloch. “Her favorite people included Cecil Beaton, Chips Channon, Somerset Maugham and indeed Noël Coward himself. . . . Many of her favorite moments were spent in the largely homosexual world of the great decorators and couturiers.”

Whatever went on between them, the duke was publicly humiliated and privately hurt, and the relationship ended suddenly. According to some this was because the duke demanded it and Wallis obeyed; others claim that Donahue was eating so much garlic that his breath became offensive to both of them. “Quite apart from other differences,” Wallis wrote in her memoirs, “women seem to me to be divided into two groups: those who reason and those who are forever casting about for reasons for their own lack of reason. While I might wish it to the contrary, the record of my life, now that I have for the first time attempted to see it whole, clearly places me with the second group. Women, by and large, I have concluded were never meant for plans and planning.”

Adapted from ‘‘That Woman: The Life of Wallis Simpson, Duchess of Windsor,’’ to be published by St. Martin’s Press in March 2012.