Kate Middleton and Prince William Are "The World's Most Glamorous Royal Couple" Right Now: Expert

Prince William's 40th birthday cemented him as an incredibly beloved figure in the Royal Family. All it takes is a quick scroll through the comments on his birthday post from Prince Charles to see how much he means to royal fans around the world.

As for Kate Middleton, she is also one of the most admired royals in the world today, with fans regularly praising what they see as her poise, genuine demeanor and flawless fashion sense.

To mark Prince William's 40th birthday on June 21, royal expert Richard Fitzwilliams commented on the Duke and Duchess of Cambridge's influence and place as senior royals. And if the Cambridges have a biggest fan, it's fair to say the author would at least be in the top 10.

"Prince William’s inspiration, as he has said, is the Queen," Fitzwilliams told the Daily Star. "His partnership with Catherine and the way they work together, on charitable issues and on foreign tours, is perfection."

The expert, like many others, believes the duchess is a wonderful fit for William, and that she has a very positive influence on him.

"Catherine has not only been wonderfully supportive, but has also grown in confidence, especially as a speaker," he added. "They are also the world’s most glamorous royal couple."

For Fitzwilliams, it's very important that the Cambridges be these beloved figureheads for the Royal Family, because it then reflects well on the Firm as a whole, helping to ensure its longevity even in a changing society.

"This helps spread the word and is also useful for soft power, as the government uses [the Cambridges'] visits abroad to promote goodwill," he concluded.