Royal salutes have been fired in London and across the UK to celebrate the Queen's 91st Birthday.
At midday, 41 volleys in honour of the Queen's birthday were fired by the King's Troop Royal Horse Artillery in Hyde Park.
An hour later the Honourable Artillery Company will fire a 62-gun salute at the Tower of London.
The Queen is already the longest-reigning Monarch and achieved another milestone in February, becoming the first British sovereign to reach their Sapphire Jubilee, a reign lasting 65 years.
Her Majesty is expected to spend the anniversary privately at Windsor Castle.
Princess Elizabeth Alexandra Mary was born at 2.40am on April 21, 1926, the first child of the then Duke and Duchess of York, at 17 Bruton Street, the Mayfair home of her mother's parents, the Earl and Countess of Strathmore.
Her official birthday will be marked in the summer with the Trooping the Colour ceremony.