In a statement, the Palace said: “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.”
Clarence House confirmed Charles would go by King Charles III.
He said: “The death of my beloved mother, Her Majesty The Queen, is a moment of the greatest sadness for me and all members of my family.
“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.”
The 96-year-old, born on 21 April 1926, was the country’s longest-serving monarch, coming to the throne in 1952 after the death of her father George VI.
Earlier today, she had been placed under medical supervision at Balmoral with doctors concerned for her health.
It followed increasing concerns in recent months for her health, with the Queen suffering from ongoing mobility issues.
Her Platinum Jubilee milestone was celebrated with millions taking to the streets during a four-day weekend of national commemorations in June.
She thrilled crowds on the first day of the celebrations on 2 June when she appeared on the Buckingham Palace balcony and later at Windsor Castle.
But the next day she pulled out of the Platinum Jubilee Service of Thanksgiving at St Paul’s Cathedral after experiencing “discomfort” during the previous day’s celebrations.
In May, the Prince of Wales delivered the Queen’s Speech at the State Opening of Parliament – in what was a historic delegation of constitutional duties – and the first time the monarch had missed it in nearly 60 years.
Her reign started in the post-war years and saw many changes in the country, including devolution for Scotland and Wales, the Good Friday peace agreement and more latterly the Covid-19 pandemic.
The Queen was lauded for a speech she gave during the pandemic, watched by 24 million people, when she said that while the pandemic was a “different” challenge, “better days would come”.
She ended with the line “we will meet again”.
There were fears for the Queen’s health when she caught Covid, testing positive on 20 February.
The triple-vaccinated Queen suffered from mild cold-like symptoms but said the virus left her “very tired and exhausted”.
She carried on with light duties while self-isolating at Windsor but cancelled some virtual audiences.
Her husband, Prince Philip, died in April 2021. The couple had been married for 74 years.
She rallied to honour the Duke of Edinburgh at a memorial service at the end of March, walking slowly and carefully with the aid of a stick, and holding on to the Duke of York’s elbow for support.
Her last major engagement was on Tuesday, when she appointed Liz Truss as prime minister.
This was the first of 15 Prime Ministers in her 70-year reign that she had not appointed at Buckingham Palace.
Never supposed to be Queen
Queen Elizabeth II, whose full name was Elizabeth Alexandra Mary Windsor, was never supposed to be Queen.
Born on 21 April 1926, during the reign of her grandfather, George V, she was at the time third in line - behind her uncle, Prince Edward, and her own father, Prince Albert.
She was assumed to be a relatively minor royal, as Prince Edward was still young and expected to marry and produce an heir and Prince Albert could have still fathered a son.
The young princess grew up in London with her sister Margaret and enjoyed trips to Balmoral Castle in Scotland - which remained one of her favourite places for the rest of her life and is where she ultimately passed away.
‘Lilibet’, as she was called, was known for being fond of horses and dogs, and was also once called a “character” by her future first Prime Minister Winston Churchill, who once visited the family in Scotland when she was just two years old.
Heir to the throne
In 1936, her grandfather died and her uncle succeeded to the throne as Edward VIII. But a year later he abdicated in favour of his brother Albert - who became King George VI in tribute to his father.
Elizabeth was suddenly heir to the throne.
During the Second World War, she and Margaret were moved away from the Blitz and spent much of their time living at Balmoral Castle and Windsor Castle, separated from their parents.
In 1947 Princess Elizabeth went with the king and queen to South Africa. She has since become the world’s most travelled Head of State, undertaking many historic overseas visits.
Betrothal to Prince Philip
Upon her return to the UK, her betrothal to distant cousin Lieutenant Philip Mountbatten of the Royal Navy, formerly Prince Philip of Greece and Denmark, was announced.
They were married at Westminster Abbey on 20 November, 1947, and Philip became the Duke of Edinburgh.
Their first child, Prince Charles, was born 14 November, 1948, at Buckingham Palace, and they later had Anne, Andrew and Edward.
Prince Phillip died aged 99 on 9 April 2021, with the Queen describing him as her “strength and stay”.
Ascent to the throne
In 1951, the health of King George VI started to seriously decline, and Princess Elizabeth represented him at the Trooping the Colour and on various other state occasions.
On February 6, 1952, after 16 years on the throne, King George VI died aged just 56. Elizabeth became Queen much sooner than anyone had expected, aged 25.
She carried out her first state opening of Parliament on November 4, 1952 and her coronation was held at Westminster Abbey on June 2, 1953.
In November 1953, the Queen and the Duke of Edinburgh made a six-month round-the-world tour of the Commonwealth, which included the first visit to Australia and New Zealand by a reigning British monarch.
Sense of duty
Throughout her reign, Queen Elizabeth II became known for her sense of duty and her devotion to a life of service.
She has been present at many landmark events, making the country’s first ever direct dial call - from Bristol to Edinburgh - in 1958, and sending her first email in 1976.
Excluding 1969, she has made a Christmas Day broadcast for every year of her reign.
Queen Elizabeth II has continued old traditions, such as conducting the State Opening of Parliament (which she has done a total of 65 times) - and even started new ones.
Her regular duties included weekly meetings with the Prime Minister, and the Trooping of the Colour.
In her time as Queen, she has had 15 prime ministers, met with 12 US presidents, five Popes, and the leaders of all other major faiths of the UK.
In 1977, Queen Elizabeth II celebrated her Silver Jubilee - then her Ruby, Golden and Diamond ones in 1991, 2002 and 2012.
She opened the 2012 London Olympic Games with James Bond, and was called the “most memorable Bond Girl yet” by Sir Kenneth Brannagh.
The Queen thrilled crowds on the first day of her Platinum Jubilee celebrations on 2 June, when she appeared on the Buckingham Palace balcony and later at Windsor Castle.
She is survived by her children, the Prince of Wales Charles, the heir to the throne, the Princess Royal Anne, the Duke of York Prince Andrew and the Earl of Wessex Prince Edward.