On Remembrance Sunday, The King was joined by senior members of the Royal Family to mark Remembrance Sunday.
It follows from his attendance with relatives at the Festival of Remembrance, where he and Queen Camilla unveiled new statues of the late Queen and Prince Philip at the Royal Albert Hall.
King Charles led the royal party onto the street just before 11am, when a two-minute silence was held to honour the war dead from the First World War onwards.
The Queen and Princess of Wales observed the events from the balcony of the Foreign Office, also joined by The Duchess of Edinburgh, The Duke and Duchess of Gloucester, and Sir Tim Lawrence.
Cannon at Horse Guards Parade and a bugler playing the Last Post ended the silence.
Charles’ wreath, laid first as Sovereign and Head of the Armed Forces, read: ‘In everlasting remembrance. Charles R’. He was applauded after he did so, unusual at a usually silent and sombre event.
The King wore his uniform as Marshal of the Royal Air Force.
His was followed by one from The Queen, which was succeeded by Prince William and his own wreath. The Prince of Wales was wearing the uniform of the Blues and Royals, of which he is a Lieutenant Colonel.
Princess Anne, in her uniform as Honorary Rear Admiral, came next, followed by The Duke of Edinburgh, in his Royal Honorary Colonel of The Royal Wessex Yeomanry uniform.
A wreath was laid on behalf of The Duke of Kent, who did not attend the ceremony due to episodic mobility problems. In recent years, the Duke, 88, has joined members of the family on the balcony rather than placing a wreath himself.
The royal wreaths were followed by those from political leaders, including the Prime Minister, the Leader of the Opposition, the Home Secretary, the leaders of the devolved nation, Commonwealth representatives and former Prime Ministers.
Earlier in the morning, almost 10,000 veterans and 800 armed forces personnel from all three service branches took part in a march-past at the Cenotaph, with music from the Band of HM Royal Marines Portsmout, The Central Band of the Royal Air Force and The Massed Bands of the Household Division.
They were joined by thousands of members of the public who applauded them as they walked by, and thanked them for their service.
The Band of Royal Marines Portsmouth and The Central Band of the Royal Air Force joined The Massed Bands of the Household Division to play music as around 10,000 veterans marched past the Cenotaph.
2023 marks 70 years since the Korean War and 20 years since the start of the UK’s military operations in Iraq following 9/11.
Among those taking part were nuclear test veterans, who for the first time wore a medal acknowledging their contribution.
After the service, Princess Anne joined Vice Admiral Johnson, and the Secretary for Defence, Grant Shapps to take the salute on Horseguards Parade.