As he continues to tackle the job he was born to do, King Charles is lucky to be surrounded by several wise and supportive family members who do all they can to help and boost the monarchy’s image. While the King has his son, the Prince of Wales, and his brother, the Duke of Edinburgh, on hand, it is often the senior female royals who bring the star power.

Even though Queen Camilla, the Princess of Wales and the Princess Royal act as vital figures for the King, another woman who is essential to the line-up of senior royals is the Duchess of Edinburgh. Sophie, 60, has tirelessly championed campaigns against avoidable blindness, gender equality and awareness against sexual violence in conflict zones, often with little fuss or fanfare.

She is frequently called the King’s ‘secret weapon’ and continues to see a steady increase in the attention she commands.

With the Duchess gaining more and more recognition each day, a leading royal expert has explained the three reasons why Sophie is one of the greatest assets in the King’s arsenal.

Speaking exclusively to the Express, former BBC royal correspondent Jennie Bond said: “Sophie has come into her own in recent years. She is now one of the most trusted women in the King’s circle and is viewed as a senior and highly respected member of the Royal Family.

“She is also hugely relatable and a big hit with the people she meets as she goes about her work. She has a light touch and an informality that goes down well with the public.

“Charles always seems completely at ease with her. She is a sister-in-law he can trust and depend on.”

The expert’s praise is echoed by royal expert Richard Fitzwilliams. Noting that the Duchess is one of only four working royals who are under the age of 70, Mr Fitzwilliams explains: “Sophie’s path was, initially, anything but smooth.

“She and her husband, Prince Edward, had originally hoped to combine their careers with royal duties, but this did not prove possible. However, especially in recent years, she has thrived as a working royal.

“She became close to Queen Elizabeth and does a considerable amount of charitable work – with only four working royals under 70, her help is pivotal.”