Why Queen Elizabeth Was Uncharacteristically Overjoyed on Kate Middleton and Prince William's Wedding Day

Queen Elizabeth and Prince Philip depart Westminster Abbey following the royal wedding of her grandson, Prince William, and Kate Middleton.
Queen Elizabeth and Prince Philip depart Westminster Abbey following the royal wedding of her grandson, Prince William, and Kate Middleton.

Mark Makela/Corbis via Getty Queen Elizabeth on Prince William and Kate Middleton's wedding day

Queen Elizabeth had every reason to be happy as she watched Kate Middleton and Prince William tie the knot in 2011.

But she was even more emotional than expected. Courtiers have told PEOPLE that the monarch was uncharacteristically overjoyed on the couple's wedding day, content in the knowledge that the line of succession — so fraught in the years following the checkered marriages of three of her own children — was secure.

"Hearing from the Queen that you're doing a really good job, along with getting support from your husband you grow in confidence," a close royal insider tells PEOPLE of Kate in this week's cover story.

There was undoubtedly much that the Queen saw in Kate that day — and in the years that have followed — that remind her of herself.

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Prince William and his wife Kate Middleton, who has been given the title of The Duchess of Cambridge, greet the crowds along with Queen Elizabeth II (right) on the balcony of Buckingham Palace, London, following their wedding at Westminster Abbey.
Prince William and his wife Kate Middleton, who has been given the title of The Duchess of Cambridge, greet the crowds along with Queen Elizabeth II (right) on the balcony of Buckingham Palace, London, following their wedding at Westminster Abbey.

Chris Ison/PA Images via Getty Kate Middleton and Prince William's wedding day

For more on how Kate Middleton has the perfect role model in the Queen, pick up a copy of the latest issue of PEOPLE on newsstands on Friday.

Although they are separated in age by 56 years—the Queen, 96, and Kate, 40, share key qualifications for the job: quiet stoicism, unerring discretion and firm loyalty. Their opinions on contentious political issues are never heard; their commitment to the throne is unwavering, and their public images are tightly controlled.

They also married strong partners in life. Kate has said she's "in good hands" with William, while the Queen called her late husband Prince Philip her "strength and stay."

Queen Elizabeth II following the marriage of Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge at Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne was led by the Archbishop of Canterbury and was attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.

Chris Jackson/Getty Queen Elizabeth on Kate Middleton and Prince William's wedding day

Before she wed, Kate "had tea with ladies-in-waiting and briefings from private secretaries. People wanted it to work," a royal insider tells PEOPLE. "And everyone has been rewarded with [the couple's] efforts."

Alongside her husband, second-in-line Prince William, Kate is poised to enjoy a long reign in which she and William will carve their own path while honoring the traditions of the past.

Kate Middleton Rollout
Kate Middleton Rollout

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And she's doing so with the best role model available: the record-breaking monarch, 96-year-old Queen Elizabeth.

"Catherine has learned by observing," says the Queen's biographer Sally Bedell Smith. "She knows what resonates. She will have absorbed a lot from this Queen."