Prince William “will never take for granted” the special memories that his and wife Kate Middleton’s children have with their late great-grandpa Prince Philip. On Monday, the Duke of Cambridge shared a moving tribute to his paternal grandfather, as well as a never-before-seen photo of his eldest son Prince George seated beside the Duke of Edinburgh in his carriage. The sweet snapshot was taken by the Duchess of Cambridge in Norfolk back in 2015.

©The Duchess of Cambridge

“My grandfather’s century of life was defined by service – to his country and Commonwealth, to his wife and Queen, and to our family,” William began his message. “I feel lucky to have not just had his example to guide me, but his enduring presence well into my own adult life – both through good times and the hardest days.”

William also gave insight into his wife and children’s relationship with Queen Elizabeth’s husband. He wrote, “I will always be grateful that my wife had so many years to get to know my grandfather and for the kindness he showed her. I will never take for granted the special memories my children will always have of their great-grandpa coming to collect them in his carriage and seeing for themselves his infectious sense of adventure as well as his mischievous sense of humour!”

©WireImage

“My grandfather was an extraordinary man and part of an extraordinary generation,” William continued. “Catherine and I will continue to do what he would have wanted and will support The Queen in the years ahead. I will miss my Grandpa, but I know he would want us to get on with the job.”

Queen Elizabeth’s husband passed away at Windsor Castle on Friday, April 9. Following news of Prince Philip’s death, Prince William and Kate’s official social media accounts shared Buckingham Palace’s statement, which read: “It is with deep sorrow that Her Majesty The Queen has announced the death of her beloved husband, His Royal Highness The Prince Philip, Duke of Edinburgh. His Royal Highness passed away peacefully this morning at Windsor Castle. The Royal Family join with people around the world in mourning his loss.”

Prince Philip’s ceremonial royal funeral will take place April 17 at St. George’s Chapel at Windsor Castle. On Saturday, a palace spokesperson said (via AP), “Although the ceremonial arrangements are reduced, the occasion will still celebrate and recognize the duke’s life and his more than 70 years of service to the Queen, the UK and the Commonwealth.”