The power behind the throne? ‘I’m not sure Camilla would ever have been able to get through what she has over the years without sister Annabel by her side,’ writes REBECCA ENGLISH

“Sisters, sisters, there have never been such devoted sisters…I'm here to keep an eye on her…No matter the weather, we stick together…” Irving Berlin wrote.

And never has it been more fitting than when it comes to Queen Camilla and her younger sibling, Annabel Elliot.

Not only do the sisters, who were born just a year and a half apart, look remarkably similar, but they also speak to each other every day.

Some compare their bond to that of Queen Elizabeth and Princess Margaret, whose bond was forged under unique circumstances.

Or even Annabel to Charles' Anne.

And it was no surprise that Ms Elliot was one of a handful of people allowed by Buckingham Palace to speak about their relationship and the coronation for BBC One's Boxing Day documentary about the king's first year.

Their edginess was heightened by an idyllic childhood in Sussex, where they spent their free time galloping ponies across the South Downs with their charismatic brother Mark Shand, who tragically died in 2014 after a fall.

As young women, Camilla enjoyed the debutante circuit, while Annabel was more serious and preferred a quieter life. “She was a great success, but I certainly wasn't,” she has said of her sister. “I probably wasn't as confident as she was.”

After school she went to Florence to study art, followed by a successful career as an antiques dealer and interior designer, while Camilla threw herself into the countryside as wife to her first husband, the dashing army officer Andrew Parker Bowles.

But the pair remained as close as siblings could be, speaking to each other almost every day.

Annabel and her husband, businessman and landowner Simon Elliot, settled in a beautiful country house in the Dorset village of Stourpaine, where Charles and Camilla would meet on discreet weekends as they renewed their relationship after the failure of their respective marriages.

It was no coincidence that Ms Elliot herded her sister away from the hordes of waiting photographers when John Major announced his divorce from the Prince and Princess of Wales in 1992.

And it was during her 50th birthday celebration at the Ritz in 1999 where Charles and Camilla first formalized their relationship, posing together on the hotel steps for their first public photos.

The Elliots even joined the newlyweds when they honeymooned in Scotland after their 2005 wedding.

During the coronavirus pandemic, the two women even joined the short-lived House Party app so they could keep in touch during their lockdown, sources told the Mail at the time.

Mrs Elliot suffered immense grief when she tragically lost her husband of 50 years after a long illness in March, just weeks before her sister's coronation.

King Charles was among the mourners at Simon's funeral in Dorset, with police helping to close the road as the procession made its way through the streets.

This was a break with the past. Charles's late mother, Queen Elizabeth, would rarely attend funerals except in the most exceptional circumstances –

Despite the loss, Annabel still stood by her sister's side during the coronation in May. She wiped a tear from her cheek as she watched Camilla drive away from Buckingham Palace in her golden carriage.

The two women are so close that they even have similar tastes in clothing, whether it's a day out at the races or formal dresses.

If you thought a white dress by couturier Fiona Clare (a designer Camilla was introduced to by Annabel, of course) that Her Majesty wore to the Diplomatic Corps reception last month looked strikingly familiar, you're right.

It was a copy of the dress worn by 74-year-old Mrs Elliot as she took on a starring role as Lady-in-Attendance for May's coronation.

The private has occasionally crossed over into the professional, with Annabel controversially employed by the Duchy of Cornwall when King Charles was Prince of Wales as an interior designer, where she worked on dozens of commercial properties and holiday lets, as well as Dumfries House in Scotland.

Her contract was never put out to tender.

The Mail has learned that she has also recently been hired to carry out work on the King's Sandringham estate and to 'refresh' several commercial properties in Balmoral, including a major extension to the castle's gift shop.

Many expected her to become a Queen's Companion, Camilla's six close friends who have replaced the more traditional ladies-in-waiting at Buckingham Palace as her aides and gatekeepers.

But there's a very good reason why she didn't, a source said.

'First and foremost she plays the role of her sister. That sounds strange to say, but that's exactly why she's not a Queen's Companion,” they said.

“It was a very conscious decision, as neither of them wanted the balance of their relationship to be affected by a formal role.”

Another added: 'It's funny because most people concentrate [their attention] on her friends, but it is Annabel who, above all, is her rock. The queen has good instincts, just like her sister, and she trusts and relies on her implicitly.

'I'm not sure [Camilla] Without Annabel by her side, she would never have been able to cope with what she has experienced over the years.'