Alongside his wife the Princess of Wales, Prince William spoke to volunteers and operational staff at Windsor Guildhall on Thursday, thanking them for their outstanding support and "seamless operation" during the Queen's committal service.
WATCH: Prince William and Kate Middleton make special trip to Windsor
Speaking to a member of the logistics team, the royal gushed: "Certain moments catch you out. You are prepared for all, but certain moments catch you out." He added: "It is the things you don't expect that get to you," adding that he got "choked up" over the Paddington tributes.
The dad-of-three later spoke to council workers and joked about there being a new form of "competition" between Paddington Bear and the corgis. "Paddington is 'a new addition' but the corgis have been there for longer," he quipped.
The royal couple thanked volunteers
As per royal mourning guidelines, the royal couple appeared in black as a show of respect for the late Queen who passed away on 8 September. Kate looked particularly chic in a tailored black coat adorned with gold buttons, black heels and pearl drop earrings.
Prince William, meanwhile, opted to wear a smart navy suit and black tie. Members of the royal family will continue to observe the royal mourning period until Monday 26.
Prince William and Princess Kate wore black
Their surprise Windsor outing is the first time the royal couple have made a public appearance since the late monarch's poignant funeral service on Monday.
Prince William was due to make an appearance in New York on Wednesday at The Earthshot Prize Innovation Summit, but regrettably cancelled ahead of the event.
In a pre-recorded video, the royal shared a touching message in which he mentioned the late monarch. William gushed: "Although it is the saddest of circumstances that means 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 for the Earthshot Prize Innovation Summit.
Prince George and Princess Charlotte attended the Queen's funeral on Monday
"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."
Paying tribute to Her Majesty, the 40-year-old added: "Protecting the environment was a cause close to my grandmother's heart, and I know she would have been delighted to hear about this event and the support you are all giving our Earthshot Finalists – the next generation of environmental pioneers."
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