The Queen will celebrate her birthday at Windsor Castle today.
A traditional 41 gun salute will be fired in Green Park, London by the King's Troop Royal Horse Artillery at midday.
An hour later, the Honourable Artillery Company will fire a 62 gun salute from the Tower Wharf by the Tower of London.
To mark her 88th birthday, a portrait by British photographer David Bailey has been released.
The picture was taken in March and commissioned on behalf of the Government's GREAT Britain campaign.
The Queen has two birthdays, her actual one is today whilst her official one is in June.
Her birthday in June is celebrated with the Trooping the colour parade.