It also noted that Catherine was the first royal bride to have a university education.
For their wedding anniversary, the couple visited IntoUniversity, which they raised money for when they first got married.
In their post, the couple described it as “a charity that aims to help young people reach their full potential in education and beyond”.
“Proud to know that IntoUniversity benefited from the Royal Wedding Gift Fund in 2011 and continues to provide academic support for those who need it most today.”
The then Duke and Duchess of Cambridge were married in April 2011 at Westminster Abbey. Photo / Getty Images
The Prince and Princess met at the University of St Andrews, according to the BBC, and spent their first three years of married life in Anglesey, where Prince William trained to be a search and rescue pilot with the Royal Air Force.
“I loved my time up here. It was great fun … I do miss it. I miss the job, I miss the camaraderie,” Prince William told trainees at the station on Tuesday, the BBC reported.
“Your time up here will go quickly, that’s the thing. You’ll look back with fond memories,” he said.
William is next in line to the throne, meaning that George, Charlotte and Louis are second, third and fourth in line, according to the royal family’s website.