Operation London Bridge or Unicorn, what next after Queen Elizabeth II death?

Queen Elizabeth II has been at the helm of the monarchy for 70 years. [File, Standard]

Queen Elizabeth II, the longest-reigning monarch in British history, has died at the age of 96.

She has been at the helm of the monarchy for 70 years, after ascending to the throne in 1952 following the death of her father, King George VI.

The 96-year-old died on September 8, 2022, leaving a gap for the majority of the British population, who have never known life without the Queen.

But what happens when the Queen dies?

There is a lot of uncertainty about what will actually happen, as it has been so long since the death of a British monarch.

The last death of a monarch was in the 20th Century [1952]. The procedures that happened then might or might not be repeated.

At Buckingham Palace, arrangements for the Queen's death and the subsequent succession begin immediately.

For the next 12 days, Britain will grind to a halt, which would result in a loss of billions in earnings for the UK economy.

Her heir, Prince Charles, takes over the crown immediately. In fact, he is sworn in the next morning after the ruling monarch's death.

Prince Charles will now be King Charles or the name he prefers and will be sworn in by the "Accession Council".

Since she died at Balmoral, Scotland, the Guardian's previous reports indicate that the activities after her death have been codenamed "Unicorn".

As soon as she dies, the communication is first shared with Britain's leaders; the prime minister, the cabinet secretary, and the Privy Council Office were all to be informed, followed by an official public notification.

Most staff members at the palace and associated institutions will be immediately sent home once the announcement has been made.

For instance, presenters on air at BBC are to dress in mourning attire, as its theme colour changes from red to black.

Flags will be flown at half-mast until 8 a.m. the day after the funeral, according to guidance from the Greater London Lieutenancy.

Churches may also toll their bells to mark the day of the Queen's death or the day after.

The protocols government bodies will follow will emanate from the Department of Culture, Media, and Sport (though they may also originate from the palace).

Social functions will be cancelled and the Union Flag will be flown at half-mast until after the funeral, just like in the UK.

Officials will enter a period of mourning and dress appropriately (in black). Condolence books will be prepared for visitors to leave messages.

Politicians will swear allegiance to the new monarch.

Both houses will be suspended until after the official state funeral.

The Queen's coffin will be prepared to lie in state, meaning to be presented for public viewing so people can pay their respects.

The Queen's body will lie in state in Westminster Hall. There will be a short ceremony to mark the coffin's arrival, after which people will be able to file past and pay their respects. The hall will be open all but a single hour a day, the representative said.

Queen Elizabeth II's body will continue to lie in state until the day of the funeral, which will be a public holiday.

The coffin will then be transported to Westminster Abbey by gun carriage for a state funeral.

On the day of the funeral, at 9 a.m., Big Ben's bell will ring once, and then the bell's hammer will be covered with a leather pad to dampen its tones for the rest of the day.

World leaders from across the globe will come to pay their respects.

The service will be led by Justin Welby, the archbishop of Canterbury and the second-most senior figure in the Church of England (after the monarch).

The Queen will be buried at the King George VI memorial chapel at Windsor Castle.

The body of her late husband, Prince Philip, who died at age 99 on April 9, 2021, will be moved from the Royal Vault beneath St. George's Chapel to join her.

A new currency will be printed and minted immediately to reflect the new monarch.

Parts of the British national anthem will change.

Police officers will need new uniforms, as well as soldiers.

Passports and stamps will need to be updated to show the new king's head. Even mailboxes will need a change.