The royal brothers both headed to Balmoral to be with their family, united in their grief.
WATCH: Prince William's instructions to Kate, Prince Harry and Meghan Markle during joint outing
It's a place where they have some of their happiest – and saddest – memories.
William and Harry were famously staying at Balmoral when they learned of the death of their mother, Princess Diana, in 1997.
William and Harry were at Balmoral when their mother died
At the time, the Queen made the decision to stay with the boys in Scotland, rather than return to London, where there was an outpouring of grief. She faced some criticism – but felt her absolute priority was her grandsons.
In a 2017 interview, Princess Anne addressed the controversy, stating: "I think my mother did exactly the right thing. I think it's absolutely extraordinary that any right-minded parent should believe... [there] would have been an alternative to bring those children down here to London in all that hoo-ha.
The brothers pictured with their father Charles on the Balmoral estate
"I just don't know how you can think that would've been a better thing to do."
Asked if it was a case of the Queen putting her grandchildren first, the Princess Royal replied: "Absolutely. I don't think either of those two would've been able to cope had they been anywhere else.
Balmoral Castle holds a special place in the royal family's heart
"That was the only good thing that happened was that they were there, and they had that structure, they had people around them who could understand, give them the time."
Speaking last year during his royal tour of Scotland with wife Kate, William addressed his loss in a speech to the General Assembly of the Church of Scotland. "I was in Balmoral when I was told that my mother had died. Still in shock, I found sanctuary in the service at Crathie Kirk that very morning," he shared.
Prince William with his mother, Princess Diana
"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."
This week, William again touched upon the death of his mother as he paid a loving tribute to the Queen.
"She was by my side at my happiest moments. And she was by my side during the saddest days of my life," he said. "I knew this day would come, but it will be some time before the reality of life without Grannie will truly feel real."
The Queen prioritised her grandsons after Diana's sudden death
William continued: "I thank her for the kindness she showed my family and me. And I thank her on behalf of my generation for providing an example of service and dignity in public life that was from a different age, but always relevant to us all.
"My grandmother famously said that grief was the price we pay for love. All of the sadness we will feel in the coming weeks will be testament to the love we felt for our extraordinary Queen. I will honour her memory by supporting my father, The King, in every way I can."
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