The sad news comes following a sombre update about from Buckingham Palace at 1:30pm UK time on Thursday saying that "doctors were concerned for her Her Majesty's health".
"Following further evaluation this morning, The Queen’s doctors are concerned for Her Majesty’s health and have recommended she remain under medical supervision," they said at the time.
The brief statement ended, "The Queen remains comfortable and at Balmoral."
Prince Charles, Prince William, Prince Harry, Princess Anne, Prince Edward, Prince Andrew and other close family members rushed to her side amid the news of her declining health, though a spokeswoman confirmed that Meghan Markle would not be accompanying her husband.
“They have concluded that this isn’t really a moment for Meghan to be there with other close members of the family,” BBC correspondent Nicholas Witchell speculated.
“Undoubtedly people will speculate about that. She might not be terribly warmly welcomed, to be terribly candid.”
Prince William’s wife, Kate Middleton, is also not travelling to Balmoral, as their children Princess Charlotte and Prince Louis had their first fool day at school on Thursday.
Born Princess Elizabeth Alexandra Mary on April 21, 1926, in London, to King George VI and Elizabeth Angela Marguerite Bowes-Lyon, she had one sibling, younger sister Princess Margaret who died in 2002.
Queen Elizabeth married Philip Mountbatten, who would later become Prince Philip, on November 20 1947 at Westminster Abbey, after first meeting him when she was just 13 years old.
As Britain was still overcoming the affects of the war, the future Queen used coupons to pay for the fabric of her dress.
With the shock death of her father King George VI in February of 1952, Elizabeth became Queen at just 25 years of age.
Her coronation was held the following year in 1953. Queen Elizabeth has since become the longest-reigning monarch Britain has ever seen, with 70 years on the throne in 2022.
Elizabeth and Philip welcomed their first son, Prince Charles, the heir to the throne in 1948. Two years later they welcomed their only daughter, Princess Anne.
In 1960, the Queen gave birth to their third child, Prince Andrew, and in 1964, their last child Prince Edward was born.
Her Majesty had eight grandchildren when she died: Prince William, Peter Phillips, Princess Beatrice of York, Lady Louise Windsor, Prince Harry, Zara Phillips, Prince Eugenie of York and James, and Viscount Severn.
She also had 12 great-grandchildren - the youngest being Beatrice and Edoardo's daughter Sienna.
The United Kingdom is now expected to go into a period of mourning for 12 days until Queen Elizabeth's funeral.
A ceremony will also be held to anticipate the arrival of the Queen’s coffin at Westminster Hall, and her body will stay at Westminster for four days.