Kate Middleton’s ‘secret power’ within the royal family is on full display behind the scenes with Prince William, a former royal staffer says

Kate Middleton has long been admired for her grace under pressure, polished public appearances and ability to connect with royal fans.

But according to former royal butler Grant Harrold, the Princess of Wales’ greatest strength might be what she does behind closed doors as she helps keep husband Prince William grounded, calm and focused when tensions arise within Britain’s royal family.

‘The power behind the throne’

Harrold, who worked for King Charles III between 2004 and 2011 and also spent time with William and Kate at the monarch’s private country residence, Highgrove, recently shared his thoughts on Kate’s role within The Firm with Britain’s Daily Express.

Speaking on behalf of Heart Bingo Online, Harrold explained that Kate is “very good at grounding William, and she’s very good at keeping him right and keeping him calm, which is what Queen Camilla‘s good at [with Charles] as well.”

Harrold sees it as Kate’s “secret power,” adding, “I’d call her the power behind the throne, and what I mean by that is she’s a very strong individual, but she’s a real support.”

Prince William’s steadying force

Harrold’s take echoes claims made by other royal authors who have written about William and Kate’s relationship over the years.

In his 2024 biography Catherine, The Princess of Wales, which was excerpted in the Daily Mail, Robert Jobson shared that one reason William’s marriage has been so successful is that Kate serves as “a calming influence.”

The royal author compared what he described as Kate’s “stable,” “blissful” and “middle-class” upbringing with William’s more turbulent childhood and suggested that her level-headed nature has helped create a more steady home life for the future king. That loving environment helped shape the way she navigates being a wife to William and a mother to Prince George, Princess Charlotte and Prince Louis, Jobson explained.

The future queen’s uncle, Gary Goldsmith, told Jobson that the mother of three is “self-sufficient, resourceful and extremely capable.”

“She comes from a family of doers and fixers. [Her mother] has taught her girls to deal with problems with calm capability, not histrionics,” he added.

Kate Middleton’s fourth child

According to another royal author, Tom Quinn, Kate’s calm demeanor has helped balance some of William’s more emotional tendencies.

Speaking to Fox News Digital about his 2025 book, Yes Ma’am: The Secret Life of Royal Servants, Quinn claimed William could sometimes grow frustrated when things didn’t go according to plan. He described Kate, meanwhile, as particularly skilled at mitigating those moments.

“Occasionally, William has little tantrums and irritations if things aren’t done the way he wants them done,” Quinn alleged.

However, “Kate is very good at managing that in the same way that she manages the tantrums of their three children,” Quinn said, adding that “there’s a joke among the staff that Kate treats William as the fourth [child] because he occasionally behaves like one.”

Quinn’s book cited a staff member who told him, “I don’t know where William would be without Kate — she hasn’t had everything done for her throughout her life, so she calms him down when he gets a bit fractious.”

Kate Middleton the peacemaker

Jobson also suggested Kate’s influence extends well beyond her relationship with William. According to the author, the Princess of Wales has often acted as a bridge between different members of the royal family and helped smooth over tensions when issues arise. A source quoted in Jobson’s book described Kate as someone who “always tries to see both sides of any dispute,” while another called her “a stabilizing influence.”