Queen Elizabeth II was the longest-reigning monarch in British history.
The Queen was born Elizabeth Alexandra Mary Windsor on 21 April 1926.
She was a princess and was not born to be the monarch but that all changed when her uncle abdicated in 1936 when she was just 10 years old.
Suddenly, her father became King George VI and she was the heir to the throne.
She was crowned in June 1953 and reigned for seven decades.
Her life has been epitomised by service and she even volunteered to serve her country during the Second World War when she was still just a teenager.
As a result, she became the first female member of the Royal Family to join the Armed Forces in a full-time active role.
The Queen maintained a close relationship with the military throughout her reign.