'Like Anne, Sophie is the gold standard of royal duty: REBECCA ENGLISH says 'King sees Duchess as a safe pair of hands' amid her steadfastly sticking to Zambia tour amid Earl Spencer drama

If anyone could write the manual on how to be royal, it would surely be the Duchess of Edinburgh.

A former PR executive before she married Prince Edward, Sophie has an instinctive understanding of image and presentation. Yet her greatest strength may be her ability to make royal duty look effortless, loyal, hardworking and, crucially, unshowy.

As the royal soap opera intensifies this week with the publication of Earl Spencer's new book, Swan Song, and the Sussexes back on British soil, Sophie has appeared to float serenely above the drama, carrying out a five-day solo tour of Zambia.

There have been serious causes, including sight loss and women's rights, alongside more adventurous moments. 

During a camping expedition she came face-to-face with a potentially deadly hippopotamus, while on a boat safari she laughed and pointed excitedly after spotting a herd of elephants on the riverbank.

It is a combination that has become something of a Sophie trademark, serious about her work, but never afraid to show her personality.

The Daily Mail's Royal Editor Rebecca English says the Duchess has struck an unusually effective balance between warmth and diplomatic purpose.

As the royal soap opera intensifies this week with the publication of Earl Spencer's new book, Swan Song, and the Sussexes back on British soil Sophie has appeared to float serenely above the drama, carrying out a five-day solo tour of Zambia 

There have been serious causes, including sight loss and women's rights, alongside more adventurous moments

'Over the years Sophie has quietly set about cultivating a group of charitable patronages that she feels strongly about and, as a result, her personal passion shines through,' she says.

These include support for survivors of rape and sexual assault used as a weapon of war, as well as preventable blindness. The latter was inspired by her daughter Lady Louise, who underwent surgery as a child for esotropia – a condition which means that both eyes do not look in the same direction.

'The issue of sexual violence is something she has learnt more about during the course of her official travels and has led her to becoming a passionate advocate against it on the world stage,' says Rebecca.

'I've seen her give a seven-minute off-the-cuff speech on the issue, without any notes on the subject. She was seriously impressive.'

Her unfussy approach to duty has also been noted by Alisa Anderson-Cole, a former royal aide to the late Queen who worked with Sophie earlier in her career.

'While all the drama is going on over the arrival in the UK by the Duke and Duchess of Sussex and the explosive publication of Earl Spencer's new book, the Duchess of Edinburgh is putting duty before self, representing the UK on a solo visit to Zambia,' she says.

Even the non-arrival of her luggage was handled with characteristic good humour.

'Typically, steadfast and unwavering in her support of the charities close to her heart, she coped with the non-arrival of her luggage by laughing it off and carrying on with engagements in her travel gear,' says Alisa.

It is a combination that has become something of a Sophie trademark, serious about her work, but never afraid to show her personality

'Who could not smile watching her unselfconsciously dance with local women who have been treated for serious eye conditions? She is not afraid to show her fun side while promoting incredibly important issues like gender equality, education and nature. Once again she has proved what a huge asset she is to the King and the monarchy.'

With King Charles due to turn 78 in November, the future of the monarchy is inevitably becoming more prominent. For Prince William, the crown is now within sight, even if his accession remains some way off.

No one can know exactly what William's reign will look like, but one thing is clear – Sophie has established herself as one of the monarchy's most dependable figures.

She could therefore become an increasingly important member of the Royal Family in the years ahead, a woman who understands that duty is as much about the unglamorous engagements as the glittering ones.

From cutting ribbons in Grimsby to attending charity galas alongside heads of state, Sophie's commitment to the role rarely appears to falter. And away from the royal calendar, her friends praise another quality: practicality.

'Members of the Duchess's circle have also often told me over the years about how much they value her friendship and loyalty,' says Rebecca. 'And they rave about how "seriously practical" she is.

'One told me how they had spent the entire weekend trying to get their new oven to work. She came over, grabbed the instructions and had it working within minutes.'

Her marriage to Prince Edward is another apparent source of stability. The couple have been married for more than 25 years and have two children, Lady Louise Windsor and James, Earl of Wessex.

Like the Prince and Princess of Wales, they have cultivated an image of a grounded family life while maintaining their public roles as working members of the Royal Family.

Sophie could become an increasingly important member of the Royal Family in the years ahead, a woman who understands that duty is as much about the unglamorous engagements as the glittering ones

Sophie is also increasingly seen alongside the Princess of Wales at royal engagements, with the two appearing comfortable in each other's company.

And Rebecca says the King regards his sister-in-law as a dependable member of the Firm.

'She and Edward are actually very sweet together,' she says. 'Although even I was surprised to hear her say, as they marked their 25th wedding anniversary, that she still fancied him in a uniform. That definitely wasn't on my royal bingo chart!

'Along with Louise and James, they are a lovely little family unit. I know the King sees Sophie very much as a safe pair of hands and her growing closeness with the Princess of Wales will only go to strengthen the family in the future.'

Rebecca adds: 'The Duchess has always been the gold standard of royal duty, much in the way of her sister-in-law. Princess Anne.

'Obviously there were some teething problems in the early days when she and Prince Edward were, rightly, publicly censured over their business activities. 

'But they took the criticism on the chin, wound down their commercial careers and devoted themselves to a lifetime of royal duties without a single complaint in public.

'I think most agree their approach to this change in circumstance was admirable and pretty faultless.'

So, for those wondering what the secret to successful royal life might be, perhaps they need look no further than the Duchess of Edinburgh.

Being a royal is rather like working for a major company – there is an established set of values, a shared purpose and, above all, an understanding that the institution comes before the individual.

Sophie appears to understand that better than most. And as the monarchy enters its next chapter, the woman who once worked in PR is quietly positioning herself closer to its centre not by demanding attention, but by proving, time and again, that she can be trusted.