• Kate Middleton and Prince William said they will miss their much-loved grandfather Prince Philip
  • The Duke and Duchess of Cambridge thanked those who offered comforting messages after Prince Philip's passing
  • The Cambridges sent out their thank you cards in envelopes from the Court Post Office at Buckingham Palace

Kate Middleton and Prince William let their supporters know that they appreciated their thoughtfulness when they were still grieving Prince Philip's passing.

The Duke and Duchess of Cambridge sent out thank you cards to those who offered them comforting words and supportive messages following the death of the Duke of Edinburgh. Gert's Royal Replies shared a snap of the card they received from Prince William and Middleton after they extended their condolences to the royal couple on Twitter.

"The Duke and Duchess of Cambridge thank you for your kind words following the death of The Duke of Edinburgh," the message read. "Their Royal Highnesses have been incredibly moved by the many thoughtful messages they have received in recent weeks. They will all miss their much-loved grandfather and great-grandfather, but your message has provided great comfort at this difficult time."

The card was sent in the usual envelope from the British Royals with a postmark from the Court Post Office at Buckingham Palace, Gert's Royal Replies wrote in a blog. The back of the card featured the Kensington Palace logo.

Furthermore, the glossy folded card had the royal couple's individual monograms on the front with W & C under the coronets of the Children of the Heir Apparent. Meanwhile, the back of the card had a photo credit for the inside photo that read "(c) Anthony Devlin."

"I have gotten condolences replies following the death of Prince Philip from other royals and will post them at some point. (Hopefully soon, if I get motivated)," Gert's Royal Replies added.

Following Prince Philip's death, the Duke and Duchess of Cambridge shared throwback photos of the senior royal with their son, Prince George, on Instagram. The picture showed Prince Philip and Prince George sitting beside each other in a carriage. The snap was taken by Middleton. Prince William accompanied it with a lengthy caption praising how Prince Philip lived his life.

"My grandfather’s century of life was defined by service – to his country and Commonwealth, to his wife and Queen, and to our family," he wrote.

The Duke of Cambridge added that he felt lucky growing up with Prince Philip because the latter guided him and he was there for him during the good times and the hardest days of his life.

"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," he continued. "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 humor!"

Prince William praised his grandfather for being an "extraordinary man" and vowed that he and his wife will continue to "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," the duke concluded.

Prince Philip died on April 9 at the age of 99. He was laid to rest in an intimate service at St. George's Chapel on April 17.

Kate Middleton and Prince William
EDINBURGH, SCOTLAND - MAY 27: Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge attend a Beating of the Retreat at the Palace of Holyroodhouse on May 27, 2021 in Edinburgh, Scotland. Jane Barlow-WPA Pool/Getty Images