King Charles III surprised well wishers as he greeted crowds outside Buckingham Palace during an impromptu walkabout.
Mourners were delighted to see the new monarch and Queen Consort Camilla as they got out of a Rolls-Royce along Stable Yard, off the Mall, this evening.
Cheers and applause rang out as they shook hands with and accepted bouquets of flowers from people who had waited for hours.
Shouts of “God save the King” were heard along with a chorus of the national anthem.
Charles and Camilla had earlier met royal fans on their way out of Clarence House.
Meanwhile, other lucky members of the public witnessed Prince William and Kate reunite with Prince Harry and Meghan Markle outside Windsor Castle earlier this afternoon.
The two couples have not been seen in public together since before the Sussexes stepped down as working royals in March 2020.
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They exited separate vehicles but walked side to by side before spending over 40 minutes meeting fans.
They looked over the flowers and messages left for the Queen - who died on Thursday - along the royal estate's gates as the crowds roared.
It had been suggested the foursome had not spoken since Harry and Meghan arrived in the UK a week ago, despite staying less than a mile apart at Frogmore and Adelaide Cottages.
But they appeared to have put their differences aside for the occasion.
Charles signed the accession oath in front of the Privy Council this morning to officially take the throne.
William, now next in line, also signed the document to become Prince of Wales.
In a busy day, Charles was then introduced to members of Prime Minister Liz Truss' Cabinet as they lined up inside the 1844 Room at the Palace.
He spent time talking to new Foreign Secretary James Cleverly and Defence Secretary Ben Wallace as they flanked the Tory leader.
Earlier, members were present for the formalities of the Accession Council at St James's Palace, televised for the first time.
Charles, 73, automatically became King when his mum died but today's proceedings, in keeping with tradition, saw the council called to make it formal.
Following the Cabinet audiences, the King spent time meeting the leaders of opposition parties, including Labour leader Sir Keir Starmer.
Ms Truss had her own first audience alone with the King on Friday following his return to London from Balmoral.
Welcoming her to the Palace, Charles told her the passing of his mother was "the moment I have been dreading".
A royal source said William personally invited his brother and sister-in-law to join him and Kate on their walkabout.
It was the first time the two couples have been seen together since the Commonwealth Day service in early 2020.
The Sussexes arrived holding hands and continued to do so at various stages of the proceedings.
All four royals, dressed in black, bent down to look at some of the many tributes left in front of the gates.
Meghan and Harry were seen chatting, but they kept a slight distance away from William and Kate.
At one point, William crouched down to read some of the messages that had been left on the cards.
Meghan rubbed Harry's back reassuringly before linking arms with him as they looked at more of the flowers.
At the end, the brothers got close and started talking to one another as they walked to greet some of the well-wishers.
But they went separate ways and went to speak to people on different sides of the road.
* This weekend, the Daily Mirror and Sunday Mirror celebrate the life of Her Majesty the Queen with a commemorative special filled with all the key moments from Britain’s longest reigning monarch.
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