There have been concerns over the Queen 's health after Buckingham Palace confirmed today that Her Majesty was put under medical supervision, following doctors voicing concerns for her health.
Prince Charles, Camilla and Prince William all rushed to Balmoral to be by her side while other members of the royal family have been informed.
Buckingham Palace issued a rare statement on the Queen's health today to say that she remains comfortable and is staying at Balmoral.
The Royal spokesman said: "Following further evaluation this morning, the Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision. The Queen remains comfortable and at Balmoral."
Her Majesty is the nation's longest-reigning monarch, having been on the throne for over 70 years.
Her reign has outlasted that of those before her, exceeding the likes of Queen Victoria and King George III by several years.
Earlier this year the Queen celebrated her Platinum Jubilee - and although celebrations were in June, it is actually February 6 that marks the official anniversary of when she ascended the throne.
She became Queen on February 6, 1952, following the death of her father King George VI, on the same date.
At the time, she was months away from her 26th birthday.
When her father tragically passed away, Queen Elizabeth II was on a state visit with her husband, Prince Philip, in Kenya.
She and her late husband had been married for just five years at the time, and were due to continue with travels on to Australia and New Zealand.
They were standing in for King George VI who had been too ill at the time to go on the trop, despite being 56 years old.
At the time of her father's death, the then-princess was at the Treetops Hotel in Nyeri, Kenya.
While she ascended the throne in February, it was not until over a year later on June 2, 1953 that the Queen was coronated.
The special event took place at Westminster Abbey, London, which is also where the Duke and Duchess of Cambridge would tie the knot in 2011.
