The Queen celebrates her 91st birthday today. Elizabeth II, the world's oldest and longest-reigning monarch, celebrated this remarkable landmark in typically low-key fashion on Friday with artillery gun salutes in London's Hyde Park and the Tower of London, and trip to Newbury Racecourse.
The Queen Elizabeth was born on April 21, 1926 in Bruton Street in central London when Calvin Coolidge was US president and Joseph Stalin had just taken control of the Soviet Union. She became queen in 1952 aged 25.
She's has been a part of the fabric of British and Commonwealth life for as long as anyone can remember. But how much do you really know about Her Majesty?