The nation is in mourning after Her Majesty Queen Elizabeth II, Britain's longest serving monarch, died at the age of 96.
Buckingham Palace said in a statement: “The Queen died peacefully at Balmoral this afternoon. The King and The Queen Consort will remain at Balmoral this evening and will return to London tomorrow.”
Her eldest son Charles is now King.
He released a statement shortly after the death of his mother, saying: “We mourn profoundly the passing of a cherished Sovereign and a much-loved Mother.
"I know her loss will be deeply felt throughout the country, the Realms and the Commonwealth, and by countless people around the world.”
Clarence House confirmed Charles will now be known as King Charles III. William and Catherine will now be known as the Duke and Duchess of Cornwall and Cambridge.
As the nation began to come to terms with the news, crowds appeared outside Buckingham Palace. As night fell on Thursday, hundreds of colourful bouquets and rows of flickering candles brightened the gates.
A thousands-strong crowd huddled under umbrellas and tearfully consoling one another.
Further back, others sporadically broke out into the national anthem and rounds of applause.
Earlier on Thursday, in a rare update on her health, the palace revealed doctors had been "concerned" and recommended the Queen remain under medical supervision.
Charles and the Queen's three other children then travelled to Scotland to be by her side. The Duke of Sussex and Duke of Cambridge also travelled to Balmoral Castle.
The Queen last appeared in public earlier in the week when as she appointed Liz Truss as prime minister.
Truss, dressed in black, addressed the nation outside No 10 following the news of the Queen's death. the PM had been informed of her passing at around 4.30pm.
She said: “We are all devastated by the news that we have just heard from Balmoral.
“The death of Her Majesty the Queen is a huge shock to the nation and to the world.
“It’s an extraordinary achievement to have presided with such dignity and grace for 70 years. Her life of service stretched beyond most of our living memories.
“In return she was loved and admired by the people in the United Kingdom and all around the world.
“She has been a personal inspiration to me and to many Britons – her devotion to duty is an example to us all.”
World leaders also shared tributes, including US President Joe Biden, who described that Queen as "more than a monarch".
French President Emmanuel Macron called her "a friend of France" and "a kind-hearted queen who has left a lasting impression on her country and her century.”
Her death brings an end to a life of service and dedication to the Crown, after seven decades as the nation's figurehead.
For the vast majority of people in Britain, she has been the only monarch they have known in their lifetimes.
In June 2022 the Queen celebrated 70 years on the throne, making her the longest serving monarch in British history and the second longest serving in the world.
In a speech to mark her 21st birthday in 1947, Elizabeth vowed to dedicate her life to the Commonwealth. She said: "I declare before you all that my whole life whether it be long or short shall be devoted to your service and the service of our great imperial family to which we all belong."
Watch: Remembering the late Queen Elizabeth II
It was a promise she would keep for the next 75 years – 70 of which would be spent on the throne.
When she was born in London, then known as Princess Elizabeth of York, the prospect of becoming Queen was only a distant possibility.
As the daughter of the then King George V's second son, she was always destined to live a privileged life, though not much in the public eye.
When her uncle, King Edward VIII, abdicated in December 1936 her father was thrust onto the throne – making her heir at the age of just 10.
In public, the Queen remained a calming presence for her reign, staying steadfast throughout wars, political upheaval and social unrest.
During her reign, the Queen oversaw 15 prime ministers, offering impartial advice and a level of consistency during even the most turbulent times.
In private, she was known as "Lilibet" to her closest family and her friends
The loss of her husband Philip, the Duke of Edinburgh, in April 2021 during the COVID-19 pandemic was described by the Queen herself as leaving a "huge void" in her life, but she kept up with royal work after a period of mourning.
In recent times, she had increasingly stepped back from royal duties amid issues with mobility – although she did make several public appearances during the Platinum Jubilee celebrations.
Her appointment of Truss as prime minister at Balmoral on Tuesday marked the first time an audience had been held with a new PM there and not at Buckingham Palace.