The Queen “has been amazing” following the death of the Duke of Edinburgh, the Countess of Wessex has said.
Sophie and the Earl of Wessex visited Windsor Castle as the military paid tribute to Prince Philip with royal gun salutes across the UK and on warships.
They took place in cities including London, Edinburgh and Cardiff, and at Hillsborough Castle in County Down.
All three of the Queen’s sons have visited her at Windsor following Prince Philip’s death on Friday.
The Duke of York visited the castle on Saturday, and the Prince of Wales travelled there on Friday afternoon.
Military personnel fired 41 rounds at locations across the UK, starting at midday and leaving a one-minute break between each round.
Hundreds of people lined Tower Bridge in London, where members of the Honourable Artillery Company fired rounds from guns facing the Thames.
And the noise of gunfire echoed out from Edinburgh Castle, where more than 100 people gathered as the salute began.
Royal Navy ships at sea, including HMS Diamond and HMS Montrose, also fired salutes in honour of the duke, who served as a naval officer during World War Two and held the office of Lord High Admiral.
Lieutenant Colonel Erica Bridge, who serves with the Royal Artillery, said a royal salute typically involves 21 rounds, but an extra 20 are fired when they are “from designated saluting stations” – such as in this instance.
Speaking to the BBC before the salutes, she said military personnel “will feel great sadness” after the duke’s death, and the salutes would “mean a huge amount”.
Prince Philip was Queen Elizabeth II’s husband of 73 years, and died at Windsor Castle at the age of 99.
Announcing the duke’s death on Friday, Buckingham Palace said: “It is with deep sorrow that Her Majesty the Queen announces the death of her beloved husband.
“The Royal Family join with people around the world in mourning his loss.”
On Saturday, the Royal Family’s Twitter account shared a photograph of the Queen and her husband, along with a quote from a speech she made on their golden wedding anniversary in 1997 in which she described him as having been her “strength and stay all these years”.
Reflecting on Prince Philip’s life for a BBC programme broadcast on Friday evening, Prince Charles described his father’s life as an “astonishing achievement”.
First Sea Lord and Chief of the Naval Staff Admiral Tony Radakin, the most senior officer in the Royal Navy, praised the duke’s “empathy, affection and engagement” with the fleet.
General Sir Nick Carter, Chief of the Defence Staff, said the duke had been a “great friend, inspiration and role model” for the armed forces.
Similar salutes were fired to mark the death of Queen Victoria in 1901 and Winston Churchill in 1965.
n Australia, a 41-gun salute was fired to mark Prince Philip’s death outside Parliament House in Canberra.
The New Zealand Army will pay tribute in the same way at Point Jerningham in Wellington on Sunday.
Meanwhile, jockeys, owners and trainers marked a two-minute silence in tribute to the duke in the parade ring at Aintree Racecourse, Liverpool.
Flags at the track are at half-mast and jockeys are wearing black armbands.
Final details of the duke’s funeral are also expected to be released this weekend.
The funeral will take place at St George’s Chapel, Windsor, but the arrangements have been amended in light of the coronavirus pandemic, the College of Arms said in a statement.
The duke will not have a state funeral and there will be no lying-in-state, in line with his wishes, it added.
Members of the public are “regretfully” requested not to attend due to the pandemic, and it is understood the Queen is considering modified funeral and ceremonial arrangements.
The Royal Family has asked people to consider making a donation to a charity instead of leaving flowers in memory of the duke, and an online book of condolence has been launched on the official royal website.
A spokesman for Windsor Great Park said tributes would be removed “respectfully” throughout Saturday and displayed within the castle grounds.
All UK government buildings have been told to fly official flags at half-mast in tribute to the duke until 08:00 on the day after the duke’s funeral.