The Queen, who turns 91 today, is Britain's longest-reigning monarch, as well as the longest serving living monarch in the world today.

The first child of the then Duke and Duchess of York, Princess Elizabeth Alexandra Mary was born at 2.40am on 21 April 1926 at 17 Bruton Street, the Mayfair home of her mother's parents, the Earl and Countess of Strathmore.

She acceded to the throne in 1952 and over the course of an impressive 65 year reign has seen a number of significant milestones.

Here is a look at Queen Elizabeth II in numbers:

3 Number of dogs the Queen has - one corgi, Willow, and two dorgis, Candy and Vulcan.

13 Number of prime ministers who have come and gone over her reign.

16 Number of general elections held during the Queen's reign.

The Queen is longest serving living monarch in the world today Credit: PA

21 Age at which the Queen married the Duke of Edinburgh in November 1947.

23 Number of waxworks Madame Tussauds has created of the Queen over the years.

70 Years of marriage to the Duke of Edinburgh.

The Queen and Prince Philip have been married for 70 years Credit: PA

72% The proportion of her life that Elizabeth II has been Queen.

601 Number of charities and organisations of which the Queen is patron.

23,816 The number of days on the throne as of April 21 2017.

The Queen attends hundreds of events each year Credit: PA

3.75m Items of correspondence the Queen has received during her reign.