Queen Elizabeth II dies - follow the latest news as the world mourns
Operation London Bridge has swung into action, dictating how the British state handles the coming days after the death of Queen Elizabeth II.
The plans set out how the country's royal family, now led by King Charles III, Prime Minister Liz Truss ― in office herself for less than a week ― the civil service, military and media should handle a changing of the guard that has not occurred for seven decades.
A 10-day timetable has begun ― the day the queen dies is known as D-Day ― and will culminate in a state funeral and her burial alongside her husband, Prince Philip, at St George’s Chapel in Windsor.
Flags have been lowered to half-staff and Prime Minister Truss made a statement, under the guidelines for D-Day. Plans are in place to ensure official websites and social media channels are used respectfully.
Prince Charles acceded to the throne the moment the queen died, a principle expressed by the motto: “The queen is dead, long live the king.” Ms Truss made the declaration in her remarks at Downing Street.
King Charles III's accession will be marked with formal ceremonies during the mourning period and he will address the nation, and the world, on Friday.
What happens today?
On Friday, a period of royal mourning was confirmed, starting from now until seven days after the funeral, the date of which will has not yet been confirmed.
The king and queen consort are returning to London after staying at Balmoral overnight and he will have an audience with Prime Minister Truss.
Funeral plans will be tackled and the new king is expected to meet the Duke of Norfolk, who is in charge of the accession and the funeral.
They are also expected to announce that the funeral day will be a public holiday in the form of a day of national mourning.
Bells and gun salutes will be staged, including at Westminster Abbey, St Paul's Cathedral and Windsor Castle. Churches across the country are being urged to ring bells at noon.
While other flags are at half-staff the royal standard, which represents the sovereign and the United Kingdom, stays flying.
King Charles's first televised address will be at 6pm where he will pay tribute to the queen and pledge his duty to serve as the new sovereign.
The prime minister and senior ministers will attend a public service of remembrance at St Paul's.
What happens next?
An accession council made up of senior politicians and officials will convene at St James’s Palace in London on Saturday to formally proclaim his succession. Prince William is now the new heir apparent.
King Charles holds his first Privy Council, accompanied by Camilla and William who are also privy counsellors, and makes his personal declaration and oath.
The first public proclamation of the new sovereign is read in the open air from the Friary Court balcony at St James's Palace.
King Charles's coronation at Westminster Abbey, where monarchs have been crowned for hundreds of years, will not take place for some time. The queen waited more than a year before her coronation in the summer of 1953.
It is believed the new monarch will embark on a tour of the UK during the mourning period and could visit sites including the Scottish Parliament and attend a church service in Edinburgh.
The queen’s coffin will be moved to Buckingham Palace before being taken in a procession to the Palace of Westminster, where she will lie in state for three days.
The palace will be opened for mourners to file past the coffin. The queue is likely to evoke memories of the days after Princess Diana was killed in a car crash in 1997.
When the queen’s husband Prince Philip died in 2021, the funeral plans were impaired by the coronavirus pandemic and the queen attended the ceremony alone.
But in the absence of virus restrictions, many mourners and foreign dignitaries will arrive in London to pay tribute to the queen.
Concerns have been raised over whether the city's transport network can handle so many visitors.
The code name London Bridge is so well known that it barely adds any secrecy to the operation, but some parts of the plan have their own titles, such as Feather and Spring Tide.
Tributes will pour in from presidents, prime ministers, religious leaders and a British public that for the most part has never known life without the queen. The Ministry of Defence will arrange gun salutes.
The media has its own plans in place, with officials aware of how the BBC was caught cold when the queen’s mother died in 2002 and one of its presenters was criticised for wearing a burgundy tie rather than black.
Rehearsals have taken place for years and it has been suggested that the BBC maintains a Cold War-era emergency alert system for moments like this.
Obituaries for Britain’s longest-serving monarch were written a long time ago.
The queen’s funeral is expected to take place at Westminster Abbey, where services were held for Diana and the queen mother. The service will be accompanied by a two-minute silence across the country.
The queen's body will then be moved to Windsor for burial. She will be laid to rest alongside her grandfather King George V, her father King George VI, her mother Elizabeth and her husband.