The usually stoic Queen was "more overjoyed than usual" on April 29, 2011, the wedding day of Prince William and Kate Middleton. The day was, of course, not only a celebration of the two, but also of the future of the monarchy, which Her Majesty the Queen holds dear.

"She was more emotional than expected," PEOPLE reported. Courtiers said of the day that "the monarch was unusually overjoyed on her wedding day, satisfied that after the tumultuous marriage of three of her children, the path to the throne, which she had been struggling with for several years, was assured."

Perhaps the queen saw in William and Kate a marriage that would last as long as her own. After all, the Queen and her late husband, Prince Philip, were married for more than 73 years until his death in April 2021; of their four children, only the youngest, Prince Edward, has never been divorced; he and his wife Sophie will have been married 23 years this summer. [This is a far cry from Prince William and his wife Diana Spencer, who had met only a few times before announcing their engagement in February 1981. Instead, William and Kate took their time and seemed very intentional in their decision to spend the rest of their lives together.

And PEOPLE magazine reported, "What the Queen saw in Kate that day, and in the years that followed, undoubtedly reminded her a lot of herself. Although 56 years apart in age, the Queen and Kate share some of the key qualities necessary for the job: quiet stoicism, solid thoughtfulness, and steadfast loyalty. Their opinions on contentious political issues are never heard, their devotion to the throne is unwavering, and their public image is tightly controlled." The Queen is helping Kate to grow deeper into her role as future queen. A close royal source told PEOPLE of Kate: "Hearing the Queen say that you are doing a really good job, along with the support you get from your husband, makes you more confident."

Kate has said that she and William "do a good job" together. Her Majesty the Queen has also found a strong partner in her husband, once calling Philip "strength and a place to stay."

Before the 2011 wedding, Kate said, "We had tea with the maid of honor and a briefing from the private secretary. Everyone wanted it to go well," a royal source told the outlet. 'And everyone rewarded [the couple's] efforts.'

To this day, Kate continues to look to her grandmother-in-law as a role model.

"Catherine has learned by observing," said Sally Bedell Smith, the queen's biographer. 'She knows what strikes a chord. She would have absorbed a lot from this queen."

Naturally, the queen was exceptionally happy on the day she learned that the monarchy would be secure for a long time.