Princess Anne is said to be ' "greatest and most reliable confidante". And their close bond was evident when she used a playful nickname while addressing her older brother on the day of his Coronation.

The siblings were seen enjoying a sweet moment in a 2023 documentary detailing the historic event. Charles could be seen being helped with his robes by attendants when Anne walks into the room, dressed in her full ceremonial uniform.

"Hello, old bean!" she says as she greets the new King, prompting Charles to chuckle before kissing Anne's hand. Notably, the monarch chose Anne to be his 'Gold Stick In-Waiting' at , a role that traditionally served as the monarch's bodyguard.

Princess Anne is known for her forthright, no-nonsense nature, and is said to be the person Charles turns to for honest advice, both in his professional and personal life.

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A royal aide told : "Camilla might be the love of his life, but Anne's his greatest and most reliable confidante. Anne's the only one with the ability to tell him uncomfortable truths and pull him back from any emotional distractions." The source added: "'s in charge of his heart, but Anne has his head and is there for him."

The siblings are known to have grown up the closest of Queen Elizabeth II's four children and are just 21 months apart in age. Former royal correspondent Wesley Kerr previously told that Princess Anne has proved that 'she can be relied on for complete discretion and unconditional love.'

According to Kerr, Anne has a unique combination of understanding of 'who and what has shaped Charles' – as well as a real desire for him to succeed. Speaking at the time of the Coronation, Kerr stated: "She is the person The King has known longest…Anne is wise, intelligent, and incredibly plugged into the modern . She understands completely who and what has shaped him and is eager for him to succeed: for the sake of their beloved mum and dad and for country and Commonwealth."

At the age of 74, Princess Anne remains completely committed to her royal role and has long been considered the 'hardest-working' member of The Firm, given the amount of engagements she undertakes each year. Just recently she was - and she had a typically direct response.

"I don't think there's a retirement programme on this particular life," she told the while on a two-day visit to South Africa, her first international working trip of the year. "It really isn't written in, no. It isn't really an option, no, I don't think so," the Princess added of any plans to cut back on her working life.

Both Anne and Charles have impressive role models when it comes to committing to a life of duty. Their father, retired from public engagements at age 96 in 2017 after spending decades as a working member of the . Their mother Queen Elizabeth II, meanwhile, never technically retired.

was devoted to duty until the very end of her life; her final engagement was a meeting with then-incoming Prime Minister on 6 September 2022, two days before her death on 8 September at the age 96.