As news of Prince Philip's death spread across the world on Friday, tributes flooded in and mourners flocked to Royal residences to pay their respects.
The Duke of Edinburgh - Queen Elizabeth II's husband - died aged 99 on Friday morning, Buckingham Palace announced.
A statement issued by the palace just after midday spoke of the Queen's "deep sorrow" following his death at Windsor Castle on Friday morning.
"It is with deep sorrow that Her Majesty The Queen announces the death of her beloved husband," the palace said. "The Royal Family join with people around the world in mourning his loss."
Watch: The wonderful life of Prince Philip, The Duke of Edinburgh
Philip, who was the longest-serving consort in British history, had returned to Windsor on 16 March after a month in hospital.
News was posted on the official Buckingham Palace website, and tributes were paid to the prince from Piccadilly Circus to Aintree Raceourse.
As people flocked to Royal residences to lay flowers and pay their respects to the 99-year-old prince, authorities urging them to stay at home due to the threat of coronavirus being spread.
Asked why she made the half-an-hour journey from Wokingham to Windsor to pay her respects, gym owner Mary Marrison, 40, told the PA news agency: “I think it’s what makes us British, having a monarchy.
“And he’s been the support of our monarch for all of our lives, and I feel like he deserves the respect.”
Flags were flown at half mast in Downing Street and at Royal residences including Balmoral and Buckingham Palace.
Patsy and John Parnell, who live in Windsor, said they would wave at the Duke of Edinburgh at events they had attended.
The couple were among dozens of people gathered outside Windsor Castle to lay flowers for Philip.
Mr Parnell said. “We’ve walked up and down this road for a long, long time and just feel like the man has reached the ripe old age of 99 and he’s done great things.
Watch: Prince Philip dies - a nation mourns
“From my point of view this is the first real big dent in the royal family.
“I know they’ve had their ups and downs but this one is so serious, I mean now she (the Queen) is on her own.
“He’s not an easy man to understand, he kept himself to himself, but nevertheless you have to admire that he was a man of principle.
“He stood by his wife and he never veered from duty, I can’t find any fault in him.”
As crowds grew in Windsor and outside Buckingham Palace, the Cabinet Office issued a statement saying it was "supporting" the Royal household by urging people not to meet and gather near royal houses, or leave floral tributes at the sites.
It is thought the measures are being encouraged to avoid any risk of coronavirus spread amid concerns that large crowds could start to gather.
The statement from the Cabinet Office read: "The sad death of HRH The Duke of Edinburgh has been announced by Buckingham Palace.
“Although this is an extraordinarily difficult time for many, we are asking the public not to gather at Royal Residences, and continue to follow public health advice particularly on avoiding meeting in large groups and on minimising travel.
“We are supporting the Royal Household in asking that floral tributes should not be laid at Royal Residences at this time.”
Watch: Princess Anne speaks about Prince Philip's legacy