The Queen is Britain's longest reigning monarch, having been on the throne for over 70 years. In fact, Her Majesty celebrated her Platinum Jubilee earlier this year.
She became Queen on February 6, 1952, following the death of her father King George VI, on the same date - just months away from her 26th birthday.
In the event of the Queen retiring or passing away, Prince Charles is heir to the British throne and will become King. He is followed by his son Prince William, who is next in line for succession to the Crown.
