The sweet comment Harry made to William as Kate walked down the aisle

Next month, Prince William and Kate Middleton will celebrate their eleventh wedding anniversary. That's right - it has been over a decade since the Duke and Duchess of Cambridge said 'I do' at Westminster Abbey in front of nearly 2,000 guests - and millions across the globe tuned in to watch their big day.

However, despite how much time as passed, royal fans are just as intrigued about the little details from their wedding as they were in 2011 - whether it's the special meaning behind the ring that William gave to Kate, the fact that they broke royal protocol or that William helped his bride-to-be with her hair on the morning of the ceremony.

And now, another detail from the day is going viral.

It has been reported that when Kate's father, Michael Middleton, walked his daughter up the aisle, William quipped: 'Just a quiet family wedding, then,' in reference to the fact that a staggering 26 million people were said to be watching around the world.

But do you know what Prince Harry said to his brother before Kate got to the altar?

The Duchess, in her iconic Sarah Burton for Alexander McQueen dress, made her way towards William, and Harry made a sweet comment to his older sibling.

In her 2013 novel, Kate: A Biography, royal author Marcia Moody wrote: 'Harry looked back as Kate started walking down the aisle and reported back to his brother, "Right, she is here now."

'Harry then said: "Well, she looks beautiful, I can tell you that."

According to the author, when Kate reached William 'the couple set eyes on each other, and William murmured to Kate, "You look beautiful."'

How lovely!