Queen Elizabeth II dies: What happens next?

London [UK], September 9 : As the longest-serving monarch of the UK, Queen Elizabeth-II died on Thursday, her seven-decade-long reign came to an end, triggering questions regarding further proceedings and transition of powers.
According to a professor of British and Commonwealth history at the University of London, Philip Murphy, the Whitehall started the planning process about what would happen when the Queen dies from the time she became one, New York Times reported.
"Much of it has been planned down to the minute, and some things have already fallen into place," he said, adding that the transition of power will be automatic as the throne cannot be left vacant and whoever succeeds her becomes king of Canada, king of Australia, king of Tuvalu.
Upon her death, Prince Charles becomes King Charles III , as per media reports.
Moreover, the national anthem of Britain will now again shift back to "God Save the King" as the British Queen breathed her last on Thursday at Balmoral castle in Scotland, according to the New York times.
According to protocol, Charles will make four traditional public statements taking up the new role and will give a personal and political inaugural declaration at the first meeting of the Privy Council.
Moreover, Charles will also make a statutory oath to uphold the Church of Scotland during the meeting of the council and confirm the timing of the queen's funeral. The day of the funeral has not been confirmed yet by the Royal family.
Lastly, Charles will take the Coronation Oath following which a proclamation will be read, declaring the reign of the new king, the New York Times reported.
The UK authorities had devised Operation London Bridge to manage events during the first 10 days between the Queen's death and the funeral. They had thought of Operation Unicorn in case the queen died in Scotland.
As per the documents seen by The Politico, Thursday was declared as "D-Day" and each following day leading up to the funeral will now be referred to as "D+1," "D+2" till the tenth of the Queen's death.
As per one official memo, the code for conveying the message of the Queen's death is "London bridge is down," following which a vast security operation to manage crowds and travel chaos is planned to be carried out.
Ten days after Queen's death, the newly appointed UK Prime Minister Liz Truss will be the first member of the government to make a statement.
Aside from the statement from the PM and other members of the government, gun salutes will be arranged at all saluting stations.
Subsequently, Liz Truss will hold an audience with the new king, and King Charles will deliver a broadcast to the nation.
The state funeral will be held at Westminster Abbey and there will be a committal service in St. George's Chapel at Windsor Castle. Thereafter, Queen Elizabeth II will be buried in the castle's King George VI Memorial Chapel.
The Queen was born on April 21, 1926, at 17 Bruton Street in Mayfair, London. She was the first child of The Duke and Duchess of York - who later became King George VI - and Queen Elizabeth.