When Princess Kate officially became part of the Royal Family on her marriage to Prince William, she had a lot to learn. She was given a lot of time and space to get used to her new royal role and luckily had help from one of the best, and most experienced tutors she could have hoped for – the late Queen Elizabeth.

In a new documentary exploring Kate’s close bond with the late monarch on Channel 5 – entitled Kate and the Queen: A Special Relationship – royal experts weighed in on just what brought the two women together so well. From Kate’s own admissions about how much the former monarch helped her adapt to royal life and supported her growing family, it’s clear that the now-Princess of Wales held the late Queen in the highest regard – and the experts have claimed that the feeling was pretty mutual.

As reported in the Daily Mail, expert Richard Kay said that in his view, the late Queen’s relationship with Princess Kate was somewhat of a slow burn and that this was part of the Queen’s personality, to take her time getting to know people properly. “The Queen grew to trust Kate. I don’t think she really trusted anyone on first impression, we’re all performing the same show, the show is supporting the Queen. But with Kate and the Queen, it grew deeper than that, there was a real grandmotherly affection between the two,” claimed the expert.

Another royal expert – Victoria Murphy – pointed out that the two women shared an incredible common link, that enabled them to develop such a deep bond over time with their common ground as a foundation for their relationship. “Right from the beginning, Kate had a lot more in common personality-wise with Elizabeth. They have something about them which has that inner poise and the capacity to lead and command respect,” the expert claimed.

In 2016, Kate paid tribute to her grandmother-in-law in a documentary to mark Queen Elizabeth’s 90th birthday. Kate explained how the monarch had helped her get used to her royal duties by accompanying her on a solo engagement in the early days of her marriage, and the late Queen’s sense of duty that permeated her life and public role. However, she also revealed the aspects of the Queen’s private personality that she respected.

“I suppose what’s really struck me is her love for the simple things in life. You would expect a lot of grandeur and a lot of fuss and things, but actually what really resonates with me is her love of simple things, the lack of fuss and I think that’s a special quality I think to have.”