Prince Philip conducted 219 royal engagements a year ago, and was in good form when he opened a new stand at Lord's Cricket Ground in London on Wednesday.
While few were surprised that Philip is stepping back, tourists outside the imposing gates of Buckingham Palace expressed unhappiness about the news.
"Thereafter, the Duke will not be accepting new invitations for visits and engagements, although he may still choose to attend certain public events from time to time", the statement said.
Prime Minister Theresa May led the tributes to the Queen's consort, saying he has given the monarch "steadfast support", while Labour leader Jeremy Corbyn said the duke's "clear sense of public duty" had inspired people for more than 60 years.
The royal looked relaxed as he attended a reception for members of the Order of Merit at St. James's Palace Thursday, alongside Queen Elizabeth II.
When mathematician member Michael Atiyah said to him: "I m sorry to hear you re standing down", the duke replied: "Well, I can t stand up much longer!"
Prince Philip still has scheduled appointments to make between now and his official retirement in August, many of them accompanying the Queen, and plans to fulfill those obligations.
Alan Doyle, 47, a guide with London Tailored Tours, added: "He has supported the Queen, he's been her rock".
May said Prince Philip s contribution to Britain, the Commonwealth and the wider world would be "of huge benefit to us all for years to come".
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Lorenzo Insigne added Napoli's third goal in the 62nd minute, while Diego Farias netted a consolation for the visitors in stoppage time.
Prince Philip has been ever-present at his wife s side since she took the throne in 1952.
The meeting was called somewhat last minute, leading many to fear that some actual emergency was taking place at the palace.
Philip may feel the monarchy is in good hands, with the line of succession extending to William and Kate's children, Prince George, 3, and Princess Charlotte, who just turned 2.
He is not expected to disappear completely from the public stage; the palace said he may still take part in some events from time to time.
The announcement followed a meeting of royal staff from around Britain, which prompted speculation about the health of the Queen and her husband.
One of the officials said the meeting is not related to the health of any senior royals.
Elizabeth and Philip celebrate their 70th wedding anniversary in November. She has described him as "my strength and stay".
It is likely that the monarch will be accompanied by younger members of the royal family on future engagements.
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