Britain's Prince Philip, who is 95, will no longer carry out public engagements from autumn of this year, Buckingham Palace has announced.
The Palace said in a statement it was the Duke of Edinburgh's decision taken with the support of the Queen, his wife.
The statement read: "His Royal Highness The Duke of Edinburgh has decided that he will no longer carry out public engagements from the autumn of this year.
"In taking this decision, the Duke has the full support of the Queen. Prince Philip will attend previously scheduled engagements between now and August, both individually and accompanying the Queen.
"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 Duke of Edinburgh is Patron, President or a member of over 780 organisations, with which he will continue to be associated, although he will no longer play an active role by attending engagements.
"Her Majesty will continue to carry out a full program of official engagements with the support of members of the Royal Family."
Last year it was revealed Prince Philip carried out nearly twice as many days of public engagements as the Duchess of Cambridge in the year he turned 95.
UK Prime Minister Theresa May has paid tribute to Prince Philip for his contribution to Britain and beyond, his "steadfast support" of Queen Elizabeth and for his patronage of hundreds of charities and good causes.
"On behalf of the whole country, I want to offer our deepest gratitude and good wishes to His Royal Highness the Duke of Edinburgh following today's announcement that he will stand down from public duties in the Autumn," she said in a statement.
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The Duke of Edinburgh's retirement from public engagements comes as the Queen and Prince Philip prepare to mark a poignant personal milestone this year.
In November, the royal couple are due to reach their platinum wedding anniversary - 70 years since they wed.
The monarch, now 91, and Philip had a busy 2016 - with the Queen celebrating her high-profile 90th birthday with a public walkabout and a private black tie banquet for friends and loved ones in Windsor Castle.
Official commemorations of the Queen's milestone anniversary were held in June 2016 - when Philip also reached his 95th birthday - and the Royal Family were out in force for a service of thanksgiving at Westminster Abbey.
The weekend of festivities included the traditional Trooping the Colour parade, and a street party in The Mall, during which the Queen and Philip rode down the famous thoroughfare, standing in an open-top "Queen-mobile", waving at the picnickers.
In 2015, the Queen became the nation's longest reigning monarch - and this year reached her Sapphire Jubilee - having now been on the throne for more than 65 years - with Philip at her side.
In just a few weeks' time, on June 10, Philip will be 96.
Staff from all royal residences across the UK had been summoned to a meeting at Buckingham Palace, in a move billed as "highly unusual" by royal watchers and leading to speculation there had been a death.
The Daily Mail initially reported that the Queen's most senior aides had called all staff to an emergency meeting, sparking speculation the 95-year-old Duke of Edinburgh had passed away.
The palace's press office refused to comment, fueling the rumour.
A conspicuous absence of royal-related information on UK news websites led many to suggest the palace and UK media were following traditional protocol for a royal death.
Journalists eventually got through to staff at the palace who said they did not believe the Queen or the Prince were unwell. A palace spokeswoman told the Herald there would be no comment about the purpose of the meeting in advance.
BBC royal correspondent Peter Hunt eventually tweeted that he had been told by a reliable source the meeting at 10am - 9pm this evening NZ time - was not about the health of the Queen or Prince Philip.
Royal writer of three decades Phil Dampier predicted earlier today with Newstalk ZB's Larry Williams Prince Philip could be announcing he was retiring from all duties.
The Prince Regent's relinquished 800-odd patronages would likely be passed to other royals such as Prince William.
It is unclear where the rumours of Prince Philip's death originated, although it could have been sparked by a hoax earlier this week when a Facebook page "RIP Prince Philip" took in hundreds of credulous social media users.
At the meeting today servants were to be addressed by the Lord Chamberlain, the most senior officer of the Royal Household, as well as Her Majesty's right-hand man, Private Secretary Sir Christopher Geidt, according to the Daily Mail.
The Express reports that Prince Philip and the Queen are due at a service in the Chapel Royal of St James's Palace in central London following the meeting with staff.