Prince William, Princess Kate make first post-funeral appearance to thank to those who helped make it unforgettable

In their first appearance since Queen Elizabeth II's funeral, the new Prince and Princess of Wales met Thursday in Windsor with volunteers and operations staffers who helped ensure Monday's committal service at St. George's Chapel went smoothly.

Prince William and Princess Catherine, or Kate as she is widely known, met with people at Windsor's Guildhall, just outside the gates of Windsor Castle. (The Guildhall is where his father, King Charles III, and his second wife, Camilla, now the Queen Consort, were married in 2005.)

William and Kate were there to pay tribute to the armies of people behind the scenes who helped make the historic funeral of a beloved and long-reigning queen a moving and magnificent final goodbye.

Among the volunteers on hand were those who helped support the huge crowds that greeted the queen's funeral cortege as it arrived in Windsor from London 25 miles away, and lined the Long Walk as it passed by on the way to the castle.

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The queen's two separate services – the funeral in Westminster Abbey in London, followed by a smaller committal service in St. George's Chapel at the castle – required military precision and planning decades in advance, with a major focus on crowd control and support.

William and Kate, formerly the Duke and Duchess of Cambridge, became the Prince and Princess of Wales (and the Duke and Duchess of Cornwall, among other titles) after his father the king bestowed the title a day after the queen died Sept. 8 at Balmoral Castle in Scotland.

The couple now lives with their three children, Prince George, 9, Princess Charlotte, 7, and Prince Louis, 4, at Adelaide Cottage, a historic house on the Windsor Castle estate that is close to the castle and to the children's new school in the nearby county of Berkshire. They also have a sprawling apartment at Kensington Palace and a country retreat on the royal estate of Sandringham in Norfolk.

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The Wales' appearance in the antique streets of Windsor on Thursday was one of three thank-you engagements by members of the royal family in the days after the funeral.

On Wednesday the queen's youngest son, Prince Edward the Earl of Wessex, honored a previous commitment, departing on a two-day trip to visit British troops and embassy officials in Estonia and Germany. He is set to thank them for their efforts during the funeral and mourning period, and for their service to the queen and now to the new head of the Armed Forces, King Charles.

The national mourning period ended the day of the queen's funeral but the king asked his family to observe another seven days of mourning set to end Sept. 26.

Also on Thursday, Princess Anne the Princess Royal, the queen's only daughter, visited Portsmouth Naval Base to meet Royal Navy personnel who took part in the funeral procession, then visited St. Omer Barracks in Hampshire to meet personnel who played a central role in providing logistical support during the funeral and other ceremonial duties.

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Meanwhile, on Wednesday, Prince William carried out another engagement via video, addressing the Earthshot Prize Innovation Summit in New York City.

"Although it is the saddest of circumstances that I cannot join you in person today, I am pleased to be able to join you in video form as you gather in New York," William told the assemblage. "During this time of grief, I take great comfort in your continued enthusiasm, optimism and commitment to The Earthshot Prize and what we are trying to achieve."

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Originally, he had been expected to be in New York to address the summit, co-hosted by Bloomberg Philanthropies and The Earthshot Prize. The latter is William's initiative to inspire and fund new climate solutions to "achieve the Earthshot mission to repair, restore and rejuvenate our planet within this current decade," he said.

William modeled Earthshot on President Kennedy's "Moonshot" challenge of 1961, which called on the U.S. to put a man on the moon by the end of that decade (which was achieved).

The 2022 Earthshot finalists in the challenge will be announced next month. In December, William and Kate will announce the second group of winners in Boston, Kennedy's birthplace, alongside Kennedy's daughter, Ambassador Caroline Kennedy, and co-hosted by Boston's John F. Kennedy Library Foundation.

"Both Catherine and I are so excited to be coming to Boston in December and we look forward to seeing you all very soon," William said.

In his video speech, William said environmental protection was a cause "close to the heart" of his grandmother the queen, who would have been "delighted" to see support for the "next generation of environmental pioneers."

"And as the Moonshot inspired a great decade of technological transformation, our Earthshot decade must inspire action, creativity and collaboration around the globe," he said via video. "Together, we need to ensure the transition to sustainable solutions is the fastest and most endemic change the world has ever known."

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This article originally appeared on USA TODAY: Prince William, Princess Kate appear Windsor say thanks to volunteers