Prince William spoke out this week to reflect on his time in Scotland, including what he views as his “saddest memory” in his entire life.

While speaking with the General Assembly of the Church of Scotland on Saturday during his royal tour, William recalled that he was in Scotland when he learned that his mother Princess Diana had been killed in a car crash back in 1997.

“Scotland is incredibly important to me and will always have a special place in my heart. I’ve been coming to Scotland since I was a small boy,” the 38 year-old royal said, according to the BBC. “As I grew up, I saw how my grandmother relishes every minute she spends here. And my father is never happier than when walking among the hills.”

“Scotland is the source of some of my happiest memories. But also, my saddest,” William continued. “I was at Balmoral [Castle] when I was told my mother had died. Still in shock, I found sanctuary in the service at Crathie Kirk that very morning. And in the dark days of grief that followed, I found comfort and solace in the Scottish outdoors. As a result, the connection I feel to Scotland will forever run deep.”

Diana was only 36 years-old when she was killed in a car crash in Paris, France while being chased by paparazzi in 1997. William was only 15 years-old at the time of her death.

While this is a painful memory for William, he made sure to add that he also has fond memories of Scotland, including meeting his wife Kate Middleton there.

“And yet alongside this painful memory, is one of great joy. Because it was here in Scotland, 20 ago this year, that I first met Catherine,” William said of Kate, who he met when they were both students at the University of St. Andrews. “Needless to say, the town where you meet your future wife holds a very special place in your heart.”

“George, Charlotte and Louis already know how dear Scotland is to both of us, and they are starting to build their own happy memories here too,” he added of their three children. “We have no doubt they will grow up sharing our love and connection to Scotland from the Highlands to the Central Belt, from the Islands to the Borders.”