Grace Kelly found the royal role tough too

The difference in the world-views of the Markles and the Windsors was always evident in the language they employed.

After her engagement to Prince harry, Meghan told Vanity Fair magazine: ‘ I was born in Los Angeles, a California girl who lives by the ethos that most things can be cured with either yoga, the beach or a few avocados.’

The Windsors were a good deal less ethereal. ‘If it doesn’t fart or eat hay, she’s not interested,’ Prince Philip once said of his daughter, Princess Anne.

During her engagement to harry, Meghan employed the soapy language of Californian mindfulness. She spoke of ‘nurturing our relationship’ and ‘focusing on who we are as a couple’. Describing their first meeting, she said, ‘ So for both of us, it was just a really authentic and organic way to get to know each other.’ Around the same time, harry spoke of their relationship in very different terms, almost as though he were a colonel welcoming new blood to the regiment. ‘For me, it’s an added member of the family,’ he told the BBC. ‘ It’s another team player as part of the bigger team and you know, for all of us, what we want to do is to be able to carry out the right engagements, carry out our work and try and encourage others in the younger generation to be able to see the world in the correct sense...’

It seemed to me then that one or other of them was going to be disappointed. In an American magazine, I posed this question. ‘Five years from now...will she be content unveiling commemorative plaques at schools and hospitals, smiling through welcoming pageants in national costume offered by C- list countries, engaging in polite conversation with foreign dignitaries of a similar status at Buckingham Palace? Or will she yearn for something less dogged and dutiful, something with more zip?’

I went on to predict that, ‘ In years to come, Meghan may look back on her wedding day as the high-point of her life as a royal... Interviewed by the BBC, she said that one of the first things she and harry ever talked about “was just the different things that we wanted to do in the world and how passionate we were about change”. But life as a royal is little more than a stuffy succession of meals with mayors, dignitaries and foreign bigwigs, and the younger brother and his wife will inevitably be given the duller, less important ones.

‘At these meetings, taking a polite interest and saying nothing controversial is the order of the day. The Royal Family maintains its position by keeping well away from politics, or anything remotely radical. This is not the life for someone who dreams of changing the world.’

I gave it five years, but that has proved optimistic. Some have compared Meghan to the Duchess of Windsor, and there are certainly similarities: both Americans, both divorced, both forceful, both aghast at the endemic stuffiness of the house of Windsor. But there are differences, too. The Duchess of Windsor started from a position of unpopularity: she had few illusions about the shifting affections of public opinion. Meghan Markle, on the other hand, is an actress who craves applause; she needs to be loved.

In many ways, a closer parallel is to Princess Grace of Monaco. Grace was a huge hollywood star when she decided to marry Prince Rainier in 1956, picking up so many titles — twice a Duchess, once a Viscountess, eight times a Countess, four times a Marchioness and nine times a Baroness — that she instantly became the most titled woman in the world.

BUT after five years, she was bored stiff. In 1961, Alfred hitchcock, who had directed her in To Catch A Thief and Dial M For Murder, suggested that she should star in his new film, Marnie. Princess Grace accepted his offer and the filming was scheduled, but she had reckoned without the priggishness of the people of Monaco, who were horrified at the idea.

Accordingly, Grace abandoned the film, and returned to her monotonous life as a princess. By chance, in March 1981, she met Prince harry’s mother, Princess Diana, when she was undertaking her first public engagement as a future royal. Diana was distraught at the pressures on her. Putting her arms around her, Princess Grace tried to comfort her with a joke. ‘Don’t worry dear,’ she said, ‘You’ll see — it’ll only get worse.’