Guns saluted the Duke of Edinburgh Saturday across the UK, in Gibraltar and the rest of the British Commonwealth and from battleships at sea.
Tributes flooded in for a man who was a pillar of strength for Queen Elizabeth during her 69-year reign.
Westminster Abbey tolled its bell every minute. It rang 99 times to pay respect to each year of the duke's life.
A period of royal mourning will continue for 30 days at all royal homes where guardsmen are already donning black armbands.
As a result of the coronavirus opportunities for the Commonwealth to express its sorrow will be limited.
Philip was recently confined for one month at two hospitals in London. He underwent heart surgery and was treated for an infection before returning in the middle of March to Windsor Castle, where he died.
Queen Elizabeth's husband of 73 years, Prince Philip, died Friday. He was the longest-serving royal consort.
"The duke earned the affection of generations here in the U.K., across the Commonwealth and around the world," British Prime Minister Boris Johnson told the BBC.
Prince Philip retired from public life in May 2017 at 95. He married the Queen in 1947.
The Royal College of Arms has confirmed that Philip's body will lie at Windsor Castle until his funeral at St. George's Chapel. There will be no public viewing.
Flowers were piled high outside royal residences as mourners paid their respects to the 99-year-old prince who had spent more than seven decades at the heart of the British monarchy.
"We're all weeping with you, Ma'am," read the front page of the Sun tabloid, while the Daily Mail ran a 144-page tribute to Philip.
Buckingham Palace is expected to announce details of Philip's funeral later Saturday, although it is likely to be a small, private affair, stripped of the grandeur of traditional royal occasions by COVID-19 restrictions and the prince's own dislike of people making a fuss.
Despite a request from the royal family for the public to obey pandemic social distancing rules and avoid visits to its residences, people laid cards and bouquets outside Windsor Castle and Buckingham Palace through the night.