Her Majesty Queen Elizabeth II turns 90 today and celebrations are being held across the UK to honour her. Guinness World Records is marking the occasion by taking a look back over the monarch's incredible record-breaking history...
The much-loved monarch became the Longest reigning queen on the 9 September 2015, after she exceeded the reign of Queen Victoria which had lasted an incredible 63 years, seven months and three days from 20 June 1837 to 22 January 1901.
Born Elizabeth Alexandra Mary on 21 April 1926, Elizabeth took to the throne on 6 February 1952, following the death of her father, King George VI.
(The title for the overall Longest reigning living monarch, however, continues to be held by King Bhumibol Adulyadej (Rama IX) of Thailand, who ascended to the throne on 9 June 1946 and has reigned without interruption ever since - a remarkable 69 years, 3 months.)
Queen Elizabeth II visits GWR HQ 2005
Queen Elizabeth receives a copy of our 50th anniversary edition from GWR President Alistair Richards in 2005
Elizabeth II stands as the queen of 16 of the 53 member states in the Commonwealth of Nations, as well as being Head of the Commonwealth and Supreme Governor of the Church of England. The Queen’s official title is: "Elizabeth the Second, by the Grace of God of the United Kingdom of Great Britain and Northern Ireland and of Her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith".
The year 2002 saw The Queen's Golden Jubilee, marking 50 years since The Queen's Accession.
The Queen Diamond Jubilee
Now, at the age of 90, she holds the record for the Oldest British monarch in history, exceeding the reign of King George III (1760-1820), who was King until the age of 82.
Her Royal Highness is also the Oldest current monarch, following the death of the previous holder, His Majesty King Abdullah Bin Abdulaziz Al Saud of Saudi Arabia, who died aged 90.
She also holds the Guinness World Records title for Most currencies featuring the same individual, appearing on the coinage of at least 35 different countries. 
The Queen's lengthy reign gives rise to another Guinness World Records title, Longest heir apparent. Since his mother acceded to the throne on 6 February 1952, Prince Charles has been heir apparent for over 63 years, passing the mark set by his great-great-grandfather Edward VII, who finally took to the throne upon the death of Queen Victoria on 22 January 1901 after more than 59 years as heir apparent.