Sixty-two rounds were fired near Tower Bridge beside the River Thames by the Honourable Artillery Company (HAC), and 41 rounds beside Park Lane by the King’s Troop Royal Horse Artillery (RHA).
The HAC, in ceremonial dress, were seen driving in liveried Pinzgauer vehicles through the City of London past a thousands-strong crowd of watchers.
They travelled with police escort to the Thames riverbank, where guns were positioned facing HMS Belfast.
At the Tower of London, a royal salute comprises the traditional 21 rounds, another 21 rounds signifies the loyalty of the City of London to the Crown, and a final 20 rounds were fired as the tower is a royal palace and fortress.
Shouts of “Long live the King” were heard as spectators lined up across Tower Bridge and along the Causeway inside the tower to watch the display.
Salutes were also fired from Cardiff Castle, Edinburgh Castle, Gibraltar, Colchester, York, Larkhill near Stonehenge, naval bases in Devonport and Portsmouth and a number of stations at sea.
Among the Royal Navy ships available to fire rounds were HMS Montrose, in the United Arab Emirates, and HMS Lancaster, in Portugal.
Gun salutes have taken place in all four nations of the United Kingdom and on board Royal Navy ships at sea, to pay respects to The Queen after 70 years of service to the country. pic.twitter.com/dSnDrGPbiY
— Ministry of Defence 🇬🇧 (@DefenceHQ) September 10, 2022
Reservists from 206 Battery 105 Regiment Royal Artillery fired the salute at Hillsborough Castle in Co Down watched by Steve Baker, minister of state for Northern Ireland.
The salutes were timed to coincide with the Principal Proclamation of the King, which was read by Garter King of Arms at 11am from the balcony above Friary Court, St James’ Palace.
Coldstream Guards and the King’s Guard were present alongside eight state trumpeters of the Household Cavalry.
The RHA is a British Army mounted ceremonial unit that fires royal salutes on royal anniversaries and state occasions, such as state visits and royal birthdays.
The HAC dates its origins back to 1537, making it the oldest regiment in the British Army.
It took over the role of firing gun salutes from the Tower of London in 1924.
Gun salutes are customarily fired, both on land and at sea, as a sign of respect or welcome.
They are now used to mark special occasions on certain days of the year, many of them with royal associations.
Gun salutes occur on royal anniversaries including Accession Day, the monarch’s birthday, Coronation Day, the monarch’s official birthday, the State Opening of Parliament, royal births and when a visiting head of state meets the monarch in London, Windsor or Edinburgh.
The Ministry of Defence said there are historical records of salutes taking place as early as the 14th century when guns and ammunition began to be adopted widely.
Major Matt Aldridge, who gave the order of fire at the Tower of London, said: “It’s been an immense privilege for the soldiers of the Honourable Artillery Company to have fired the salute today at the Tower of London.
“This historic moment marking the accession to the throne of our new King will be a huge source of pride in our service to the Crown for years to come.”