KATE MANSEY: Thank goodness for Solo-Sophie, the Duchess of Edinburgh. She’s been landed with a gruelling long-haul agenda – but it’s crucial to our thinly stretched Monarchy

While all eyes have been on the state visit to Kenya followed by the celebrations for Charles’s 75th birthday, some other royal appointments have attracted less attention.

Sophie and Edward, in particular, are emerging as under-the-radar royals, taking the strain of important visits – many of them long haul – while other front-line royals are engaged elsewhere.

Last week, Sophie, Duchess of Edinburgh returned from a five-day visit to Canada, where she is Colonel-in-Chief of the Lincoln and Welland Regiment and Patron of two Toronto hospitals.

Last month found the duchess in Ethopia with little fanfare and no huge entourage.

Duchess Sophie, 58, is fast becoming one of the most important members of King Charles’s slimmed down monarchy alongside her husband, the Duke of Edinburgh. Pictured: The Duke and Duchess celebrating the 75th anniversary of the NHS at Westminster Abbey in July

It has only been eight months since Prince Edward’s wife, Sophie. became the Duchess of Edinburgh.  She has embraced the role and her ever-growing royal responsibilities. Sophie and Edward  are pictured during the Order Of The Garter Service at Windsor Castle in June

The new power quartet upon whom King Charles relies: the Prince and Princess of Wales are y Prince Edward and Sophie, Duke and Duchess of Edinburgh, as they leave Westminster Abbey after the Coronation. Prince Louis walks between his parents

The hard-working Duchess of Edinburgh was the first Royal to visit South Sudan last year

Her private secretary Alexander Stonor and her Assistant Private Secretary Annabelle Galletley were the only ones to travel with her. 

Meanwhile, her husband Prince Edward, the Duke of Edinburgh has his own full itinerary, which has included recent visits to Turkey and Bahrain on official business.

They are, in other words, extremely busy – even it it’s other members of the Royal Family who dominate the nation’s Instagram feeds.

There is plenty to do. In fact, With the Duke and Duchess of Sussex departing for a new life in America and the Duke of York out of the picture, Charles III’s slimmed-down Royal family is starting to look thinly spread.

While the King is in good health, he will nevertheless be celebrating his 75th birthday later this month alongside a 76-year-old Queen who is known to dislike long-haul air travel.

Over the course of the next decade their foreign will have to be carefully considered.

William and Catherine have youth on their side, but they also have a young family to juggle and are determined to offer the children as normal a childhood as is possible in the circumstances.

Thank goodness, then, for Edward and Sophie, who share much of the royal burden, often the less glamorous bits.

At 59 and 58, respectively, they still have time on their side. Their children are more independent now they’re older, meanwhile.

Lady Louise celebrated her 20th birthday earlier this month; son James, now the Earl of Wessex, is 15.

Could there be a future role for Lady Louise once she has finished her University degree? Given her poise and maturity – like mother, like daughter – we might hope so.

For it has only been eight months since Sophie became the Duchess of Edinburgh yet already she has done so much.

It is clear that she is fast becoming one of the most important – and hardest working – members of the Royal family.

She doesn’t always attract huge publicity for her work and she certainly does seek it, but it’s of huge value, all the same.

Sophie has criss-crossed the globe. She was the first Royal to visit South Sudan and last year she flew to New York to tell the UN that women’s rights had ‘regressed’ in Afghanistan.

All this is done with her innate sophistication and elegance.

In Canada last week she visited a rehabilitation centre and proved herself to be down-to-earth by slipping off her court shoes and donning a harness in stockinged feet to better understand how medics treat their patients.

In an illustration of both good manners and thoughtfulness, Sophie wore a special diamond maple leaf necklace which has been in her collection since 2013.

Sophie shows she is a good sport, slipping off her court shoes to try the equipment at the Toronto Rehabilitation Institute in Canada last week

Sophie saw the crucial work carried out by UNICEF in the Sabacare IDP Camp in Ethiopia in October

The Duches join Prince William to meet global conservation leaders at a private screening of the RHINO MAN earlier this summer in June

Her importance at the heart of the Royal family was underlined in June when the duchess was invited to join Prince William to meet global conservation leaders at a private screening of RHINO MAN – a feature-length documentary highlighting the fight against the illegal wildlife trade.

Such a close connection with the heir to the throne, and an equally warm friendship with his wife the Princess of Wales, will no doubt be crucial in the coming years.

It’s looking crucial right now.