Queen Elizabeth II has died and her eldest son Charles has become the oldest King to assume the British throne.
Most people in the United Kingdom and Commonwealth countries, including Australia, have never known a monarch other than Elizabeth.
The plan for what happens now she has died, known as London Bridge, is unfolding and Charles has begun his reign.
Here's what to expect.
Charles will be King Charles III
Charles has decided to go by his given name rather than choose what is known as a regnal name instead.
He will be known as King Charles III.
Queen Elizabeth II famously chose to keep her given name when she ascended to the throne in 1952.
Her father chose to reign as King George VI, but his full name was actually Albert Frederick Arthur George.
Will Camilla be Queen?
Camilla will be styled the Queen Consort.
The royal consort is the traditional position of the spouse of a ruling monarch, and most kings' wives have adopted the title Queen Consort, with a few exceptions.
Camilla's future title had been a contentious issue, and in the early years of her marriage to Charles it had been expected she would be Princess Consort once he took the throne.
But the Queen herself ended the debate in February 2022 when she said it was her "sincere wish" that Camilla be Queen Consort.
At the time of her marriage to Charles there had been debate about whether Camilla should get the title of Princess of Wales.
But it was decided it would be inappropriate to give her a title so closely associated with Charles's first wife, the late Princess Diana, so she became Duchess of Cornwall instead.
What will happen now?
Charles became King the moment Queen Elizabeth II died.
The Accession Council will meet at St James's Palace in London to proclaim him King at 9am on Saturday, UK time (7pm AEST).
Charles will take the oath that unites the churches of England and Scotland, known as the accession declaration.
The proclamation of the new sovereign will then be read out from a balcony in St James's, as well as at key locations across the United Kingdom and the Commonwealth.
Both houses of Britain's parliament will be recalled so its members can take an oath of allegiance to the new King.
Leaders of the Commonwealth, including Australia's Prime Minister Anthony Albanese, will speak in honour of the Queen and likely welcome Charles as King.
The bells of Westminster Abbey and St Paul's Cathedral are expected to toll for one hour at midday on Friday, UK time.
Gun salutes will be fired throughout England, Wales, Scotland and Northern Ireland.
When is Queen Elizabeth II's funeral?
The Queen's funeral is expected to be held 10 days from now at Westminster Abbey.
Her body is currently at her estate at Balmoral, in north-east Scotland.
It is expected it will be taken to the nearby city of Aberdeen on Friday morning, then loaded onto the Royal Train for the journey south to the Scottish capital Edinburgh.
As part of Operation Unicorn, Scotland's plan for the Queen's death, an honour guard will be formed by members of the armed forces and emergency services on every platform of the route.
The Queen's body will lie at Holyroodhouse, the official royal residence in Scotland, before travelling up Edinburgh's historic Royal Mile to St Giles' Cathedral, where people will have a chance to pay their respects.
Ceremonies will be carried out in the Scottish capital before the Queen's remains are put back onto the Royal Train for the journey south to London.
In London she will lie in Buckingham Palace's throne room before being placed onto a gun carriage for the journey to Westminster Hall.
After a short service, the official period of lying in state for four days will begin.
The coffin will be guarded by members of the British armed forces as members of the public and VIPs file past to pay their last respects.
The new King will also pay his respects during this mourning period.
On the day of the funeral, the Queen's coffin will be carried the short distance to the medieval Westminster Abbey as the chimes of Big Ben ring out across the city.
The country will grind to a halt, with crowds expected to flood the streets of London while millions watch on big screens around the country.
Where will Queen Elizabeth II be buried?
Queen Elizabeth II will be buried in the King George VI Memorial Chapel at St George's Chapel in Windsor.
The body of her husband Prince Philip, who died in April 2021, will be moved from the Royal Vault so the two of them can lie together.
The Queen's father, King George VI, and the Queen Mother were buried in the same place after their deaths.
The ashes of her sister Princess Margaret, who died in 2002, are also held there.
Crowds are expected to line the 37-kilometre stretch of road between the Abbey and Windsor Castle as the Queen's coffin is driven to her final burial site in a hearse.
When is Charles's coronation?
Charles's coronation could be more than a year away, to allow for the appropriate period of time to mourn the Queen.
The coronation is a formal ceremony in which Charles will be physically crowned King.
It will likely be at Westminster Abbey, which has held every coronation since 1066, as well as various royal weddings and funerals.
Queen Elizabeth II's coronation on June 2, 1953, was held 16 months after her father's death.
King George VI only waited five months for his coronation on May 12, 1937, but that was because it had been planned for his brother Edward VIII, who abdicated in December 1936.
The time between King George VI's coronation and the death of his father, George V, was 15 months.
The coronation of the monarch is presided over by the Archbishop of Canterbury.
Charles became the first child to witness a parent's coronation when he attended his mother's coronation as a four-year-old.
His sister Princess Anne did not attend the ceremony because she was considered too young.
Like his mother's, Charles's coronation will be broadcast live, but it will be the first coronation of a British monarch to be shown in colour.
