Once the Duke of Sussex's royal support network falls away, the Duchess will find she has a new role to play, says Anna Pasternak
When the Sussexes married in May 2018, we wanted to believe in happily ever after. Prince Harry finding true love was cause for celebration and, as a nation, we were rooting for the young couple.
Less than two years later, we are faced with the seismic news that Harry and Meghan are to be semi-detached royals, living largely in Canada. This week, the Duke performed what may be his last official duty as a senior royal, laughing with something approaching relief as he launched the Rugby League World Cup at Buckingham Palace. It has also been reported that staff at the couple's Windsor home, Frogmore Cottage, have been "redeployed".
The consensus seems to be that this partial abdication proves the immortal phrase reported at the time of their nuptials: "What Meghan wants, Meghan gets." Reluctant to be a silent ribbon-cutter, "progressive" Meghan appears determined to have it all. She wants her modern marriage and her royal husband on her terms - and her terrain, having previously lived in Toronto while filming Suits.
But if history has taught us anything, it's that the real work will now begin for Meghan. When Edward VIII abdicated to marry Wallis Simpson in 1936, he never paused to consider the complex emotional implications the decision would have for his wife. More prescient than him, Wallis - who burst into tears at the first mention of abdication - could see that she would be blamed in perpetuity for stealing a popular king from his throne and almost destroying the monarchy. The relationship that began as a thrilling coup de foudre for the former ruler became a Faustian pact for his wife.
Meghan should look to her predecessor - the first American Duchess - to see that, once Harry's royal support network falls away, she will have a new role to play.
Suddenly, without his family and roster of royal duties - everything that has given structure and meaning to his life - Harry's sense of purpose will demand detailed attention from his wife. While Meghan will be inundated with exciting opportunities, his future is far less certain. He appears to have admirably put Meghan's happiness first while she settled into his world; now, it will have to be the other way around.
The onus will be on her to ensure that this monumental sacrifice has been worth it. She may well find, as Wallis did, that this becomes onerous. The "us against the world" mantra fast exposes any relationship flaws and requires a backbone of committed steel not to buckle.
For Wallis and Edward, there remained a seam of guilt that underlay their marriage. He had turned her into the most hated woman in the world, while she felt responsible for taking him away from his country. Their marriage became an overcompensation for this. It had to work; they couldn't let a sacrifice of such monumental proportions be in vain.
Once the banished couple settled in Paris, it began to sink in that the Duke - then not much older than 35-year-old Harry - had nothing to do. Idle restlessness gave him time to nurse his grievances against his family and dwell on injustices.
While Wallis filled his life as much as she could, neither had anticipated a life of obscurity. She told the writer Gore Vidal: "I remember like yesterday the morning after we married and I woke up and there was David standing beside my bed with this innocent smile, saying: 'And now what do we do?' My heart sank. Here was someone whose every day had been arranged for him all his life and now I was the one who was going to take the place of the entire British government, trying to think up things to do."
Harry may not be a king renouncing the throne, but Meghan will have to be similarly diligent towards a man who, rather like his great-great-uncle, does not seem to be as emotionally resourceful as his wife.
In France, Wallis immediately created a life for herself. The Duke's empty existence consisted of trawling after her.
Each evening, she would have French lessons. In the course of researching my book, I met the daughter of Wallis's French teacher, who said how bright and lively she had been. How keen to learn French, unlike the Duke, who never spoke a word of the language. Instead, he would whine that, during her lessons, "he had no one to talk to".
Every day, a programme for the Duke was put on the table in the hall. Pitifully, it detailed which guests were coming for lunch and what time his golf lesson would be. "None of it was important," said Diana Mosley, the couple's friend, "but all his life he had been accustomed to a programme, and the Duchess wisely saw to it that he should have one."
While it is unlikely that Harry will trail around after Meghan in such a needy, claustrophobic manner - fortunately, they have baby Archie to further occupy them - he will rely on her more heavily than before. She will be responsible for his social circle, as it will be her friends that they mix with. Already, it has been reported that the couple spent Christmas with the Duchess's best friend, Jessica Mulroney, and her family.
Let's hope that Meghan has the patience and fortitude of Wallis. The Duchess of Windsor had to cocoon the Duke from the mundane aspects of non-regal life. Like all royals, he had never carried cash, so she took care of all payments to tradesmen and oversaw the domestic side. She reined in his overzealous purchases of everything from Thermos bottles to boxes of thermometers, the former king still in the mindset of buying bulk for his many palaces.
Where Meghan is blessed - but does not seem to fully appreciate it - is that the Royal family has tried to accommodate her. Poor Wallis had to endure not only exclusion by her in?laws, but from the world at large.
Yet unlike Meghan - whose own father may testify against her in court, over a claim that a tabloid newspaper unlawfully published one of her private letters to him - Wallis knew the importance of family. It caused her unbearable pain that their exile separated Edward from his mother, Queen Mary.
In 1942, when Edward was governor of the Bahamas, his brother, the Duke of Kent, was killed in a plane crash in Scotland. Edward was consumed with grief. Wallis watched his agonies helplessly.
It was poignant that, earlier that year, she had attempted to make "one last try to reach his mother and heal the breach between them". She wrote a generous-spirited letter to Queen Mary, explaining: "It has always been a source of sorrow and regret to me that I have been the cause of any separation between mother and son and I can't help feeling that there must be moments, perhaps, however fleeting they may be, when you wonder how David is." The sweet missive received no reply.
The love affair between Edward and Wallis was a story of devotion and a heart-rending chronicle of the consequences of sacrifice - his in giving up the throne for the woman he adored, but also hers in having to put her husband's needs first for the duration of their 35-year marriage.
It remains to be seen if Meghan has the selflessness to place Harry's happiness ahead of her own.
Family may be fraught, but exile illustrates that no man - and no marriage - is an island.
The American Duchess by Anna Pasternak is published by William Collins on Feb 6.